Deciding if we really need to book day tours in these cities ahead of time. Would ideally like to just see how it goes when we are there! So what do we need to book and plan ahead? Tours? Trains? Thanks
Budapest is pretty easy to self navigate, the train from Vienna rarely fills up and if it does, there's another in an hour. Day tours out of town should be saved for at least a 4 day visit, five day better. A good one is the train up to Szentendre and the boat back. Again, no guide required.
We always go for the "Free Walking Tours" where the tourguides work for tips. They are in every European major city. And we take their pub crawl or nightlife tour the same night. It's always a great time being shown the good local restaurants and pubs--where the action is.
For my October 2018 trip to Krakow plus your list of Budapest, Vienna and Prague, I listened to as many of the Rick Steves audio guides as I could prior to my visit and chose the ones I wanted to listen to as "tour guides" once in the cities: Vienna City Walk, Vienna's Ringstrasse Tram and part of the Prague City Walk.
In Prague: I had the Prague City Card and took the (included) city bus tour, which I signed up for 30 minutes ahead. In October, the minivan was close to full. In other seasons you may need to book a day ahead or at the very least early in the morning. The value of this tour was to give me an easy Day 1 orientation to the city, after which I explored on my own with the transit feature that is part of the Prague City Card. In October, traffic for the bus wasn't bad, but could be worse in other seasons.
In Vienna: Rick's Vienna Ringstrasse Tram audio guide was my most valued guide because I was able to see so much, so efficiently, for far less money than the tourist tram (and with greater range of travel.) Combined with my 1 week Vienna TravelCard, I enjoyed being able to "hop on hop off" the trams for the duration of my visit.
In Budapest: for this final stop on my trip I was very glad that I had booked (in advance) a Grand City bus tour. In October, the bus was not full. Again, it was a great Day 1 orientation before setting off on my own on foot and with my 7 day TravelCard to use the trams, metro and buses to explore on my own.
Budapest Parliament Tour: definitely sign up for this one in advance, online. A tour is your only option to see inside, and it is well worth the visit. English tours fill up fast. As others on this forum have suggested, even if you can't get an English tour, sign up for any language to tour inside. It is stunning.
I pre-booked all of my trains because I am a planner and prefer spending my time in advance researching and booking transit. The advance fares were cheaper and I'm good at sticking to my own itinerary. You may prefer the flexibility of waiting, and can still have the convenience of an online purchase for many train tickets, such as Vienna to Budapest.
TRANSIT: you didn't ask about transit passes, but they were a tremendous value for me in all 3 of your cities for self-guided touring.
If you're considering transit passes, I would research them ahead to decide if they are good value for you and to know the duration you wish to buy and where to purchase them. In all 3 cities, you should be able to buy them at your arrival train/metro station or airport. The transit ticket machines In Vienna and Budapest were easy to use, offered English language menus and took credit cards. In Prague, I bought my Prague City Card (includes Transit Pass) at Hlavni Nadrazi, the main train station, from the English-speaking kiosk agent.
In all 3 cities, I found their ease and flexibility to be well worth any cost difference and used transit more than I otherwise might have - further increasing the value. Even with the transit passes, I still walked many, many miles each day - the transit pass often got me to my starting point quickly, such as the tram up to Prague castle at opening time. I still walked 14 miles that day!
Rick gives good recommendations in his books for fun sightseeing trams in each city.
Thanks very much for all the info. We will try to check it all out! Just so many tours..of course we would like to book recommended ones!!!
The most facinating tours in Budapest for my interests involve Jewish Budapest. That's pretty much a "must" day.