Prague or Vienna

First, it sounds like you are doing a loop. I would get an open jaw ticket and just make a straight run. If that's not an option I would say it depends on what you are interested in and how much time you want to spend on a single train ride. Prague is sort of half way between Frankfurt and Budapest so you would be looking at a couple of 7 to 8 hour train rides plus a couple of hours of arrival time and transfers. The idea of a night train to Frankfurt followed by a 19 hour trip home to the states is more than my old bones would be pleased with. Vienna and Prague are two completely different environments. I guess if I had to go back to one of the two (Prague or Vienna) I might be inclined to choose Vienna but mainly because I don't like the crowds of tourists Prague. But its all personal interests so its pretty meaningless because none of the three is "better" than the others. The most solid advice I could give you might be to reverse the order of the trip and end in Budapest (on an open jaw ticket). Budapest is less expensive, less hectic and easier to navigate then Vienna or Prague. You might appreciate that at the end of a long trip. Sorry I wasn't more help.

I haven't been to Hamburg yet but you have so you won't need my opinion about Hamburg. Vienna is magnificent and grandiose, Prague is picturesque and medieval. Vienna is more expensive, has better coffee houses. Prague has cheaper and IMHO better beer. All the cities you are going to visit speak German (with the exception of Budapest). Why not to add little diversity to your collection and choose Prague which speaks Czech. To read more about comparisons between Vienna and Prague read James and my contributions under 30 Days Germany and E.Europe Itinerary Advice wanted.

I too would enjoy another visit to Hamburg. Prague is a happening place, especially for the young, it is crowded, and stays up late. Vienna would be my choice. It has lots of appeal and the pace is not so fast. Either would be a great choice so perhaps you should just select the one that best fits your travel scheme.

I agree that if you haven't already bought your air tickets, book an open jaw flight ("multi-city" on websites like Kayak), into your first city and out of your last one. It may not cost much more than a round trip, and even if it does, you save time and money not backtracking. In your scenario, you also avoid a night train (look at other threads, and you'll see that many will never take one again). Of Prague/Vienna/Hamburg: I loved Prague the most, by far. Vienna did not really appeal to me, but it certainly has lots to see and do. And Hamburg, at least in 1999 when I was there, was a bit of a snooze for me. I know that it has its champions here, but I'm not one of them (nothing wrong with it, mind you). The question of "Prague vs Vienna vs Budapest" is an eternal one, and there are as many answers as there are travelers. But you asked my opinion, and with your specific parameters: 1. As a first choice, I'd visit Prague and Vienna, and skip Hamburg.
2. As a second choice (if you want to retain Hamburg), I'd visit Prague instead of Vienna. BTW, I've been to all the cities you listed with the exception of Salzburg, and my favorites were Berlin, Budapest, and Prague - hands down. It's hard to imagine three more different places, despite them all being in "Central Europe." I think you'll have a wonderful trip, whatever you choose - but do try for open jaw flights (sorry, couldn't resist repeating the plug).

I live in San Antonio and when flying to Europe on Delta have to change in either Detroit or Atlanta. Its always been that way for me so I have gotten use to it. My opinion is that Prague's tourist zones are too small and confined for the number of tourists they attract. Gee, what a terrible problem for the Czech tourist industry :). It will be more comfortable in May than in June and more comfortable in June than in July and ....... I found the data some time back and I don't remember their being a significant difference between June and July; and August was the worst. I found it through Google and if you are worried you can look it up to. My last trip there was in a June (or maybe it was July) and it was too much for me. Still a wonderful town and i am glad i saw it.

You've received some good advice. I would suggest flying into Munich and out of another city "open jaw'd". And by all means, substitute another city or longer in one of the other great cities over visiting Hamburg. FYI: Prague is about 175 miles NW of Vienna, and Budapest is about 150 miles SE of Vienna. I believe in making an itinerary that's easy, and not backtracking to fly home. You get to see more, and save money. Have you considered the following: Fly into Munich Train over to Salzburg and then train to Vienna. Train down to Budapest. Train up to Prague (thru Vienna) then train up to Berlin. Train west to Cologne. If time allows, take short train trip (from Koln) into Amsterdam.
Fly home from the north end of your trip. You're wanting to tour many absolutely great cities; and every city has so much to see. You're essentially cramming 2 European trips into one. Your trip would really be better if taken a little slower.

Thanks for the many good comments. We've looked at the possibility of flying into Munich or Vienna and out of Prague, Budapest or Berlin, but it is pretty frustrating. We're trying to use Delta travel points to reserve some cash for the visit, and we can't even get a direct flight from Cincinnati to Frankfurt, let alone Munich or Salzburg. We have to go through picturesque Detroit or JFK just to get to Frankfurt. Delta all-but-abandoned CVG a couple of years ago. After pondering everyone's comments, we're thinking of foregoing the return visit to Hamburg, and including both Vienna and Prague and flying between Berlin and Budapest and possibly between Prague and Frankfurt. The comment about Prague being crowed caught my eye; will this be the case in early-Mid May?

We have visited Prague in both April and May - I would expect the historic center and the Charles Bridge to be crowded almost all the time. Prague is THE place many young europeans want to visit and they flock there. This may give you a flavor for the city - we were there early May 2012- the Charles Bridge has artists and craft folk on it selling to the tourists. As we were walking by one of the artists there was a nude girl there getting her picture drawn. We were so surprised that we walked on several steps before it fully registered just what we had seen. Prague is a place to experience at least once. In your shoes I would try to determine the best connections and expect that you will return again to fill in the missing pieces.

Prague is indeed crowded. But most people walk so called King Golden Way, that is from Wenceslas Square on Melantrichova to Old Town Square, Charles Street, Charles Bridge, Nerudova, Castle. I don't like crowds (who does?) so I get up little earlier and walk this way around 8 am. No crowds. Prague is beautiful elsewhere, too and crowds are substantially thinner away from King Golden Way.

With the help of the great comments on this post and elsewhere on the Helpline, our plans are beginning to gel. The biggest hurdle looks like getting from Prague to Frankfurt. There is the night train which is a possibility, but it arrives at Frankfurt Süd, and not having been to Frankfurt before, I'm not familiar with connections between Frankfurt Süd and the airport. The connection between Frankfurt Süd and the airport is causing my wife some anxiety as the train arrives at 4:58 in the morning. She recalls a trip in 2011 when we arrived late at night in Gare du Nord headed for CDG, only to learn there was a wildcat strike and no trains were running. It was our last day (night) before returning home, it was late, we were out of Euros, super tired, and there was only one information desk and young womans English was about as limited as my French. We spent about 3 or 4 hours with a few other stranded Americans and a lot of young people with blue and red hair and a lot of tattoos. And, I shouldn't leave out the best part, numerous teams of police officers with very big assault rifles and dogs big enough to put a saddle on. My wife was not alone in feeling it was a bit creepywe'd like to not repeat the experience in Frankfurt. I've looked into flying from Prague to Frankfurt, but many of the budget carriers don't have flights on this route; I've checked Easy Jet, Air Berlin and Wizz Air(?) to no avail. I tried one of the travel search sites and found only one non-stop flight and it was pricey. I then tried Vueling, but the site was so slow, my connection was timing out. Thoughts anyone?

Been to Prague 4 times in all different months and I wouldn't miss the city for the world. Vienna is also very, very nice. Try these two web sites for discount EU carriers: www.dohop.com
www.skyscanner.net Also when looking for one-way tickets, it is cheaper on some carriers, example KLM, to book a round trip than a one way.

Thanks to everyone for the terrific responses. With your help we've decided to omit the return visit to Hamburg and visit both Vienna and Prague instead. This way we'll have at least two full days, two nights and a part of a third day in each city. Keep an eye out for other posts; we're still pondering some other matters that will be resolved with the savvy comments on the Helpline