Central Europe Itinerary

Can't really comment on the Croatia part as I have not been there, but I think 2 days in Budapest may be too short. Never been to Bad Ischi, so I wouldn't know if 4 days would be overkill or not. Getting around by trains is really easy. Some may say this is too much moving around, but I don't think so. As long as you take into account train/bus travel and the days that you allot to each city does not include travel time.

This will begin a lot of haggling about who is right and wrong. Its all pretty personal. I like to slow down a little on my vacations and I have places I am more interested in than others. But its all personal taste so there isn't a right or wrong. So don't take any of this that way: According to Google Maps this is a 2,300km trip taking 26 hours to drive. Figure more than 50 hours by train or bus plus check-in / check-out time. Waiting, etc. maybe this will work: Comments (days are after travel time) Vienna: 1.5 days. About a full day short of a decent visit, even though Vienna isn't on my "A" list. Prague: 3.5 days. Probably about right, but you could do it in 2.5 days. One of my all time favorite hotels is here. Cesky Krumlov: You can do this as a day trip from Prague, but it's much better as an overnight stay. Lovely town. So I am going to say you are a day short. I know a great hotel here. Bad Ischl: Don't know a thing about it. But you must if you have donated 4 days (really 3.5 with transport).
Salzburg: 1 day with transportation turns out to be half a day. You are at least day short again. And I would spend 2 days, but ..... I am middle aged too. Wait while I catch my breath...........

Now we are into a few places I have never been. But one day in any town is really ½ a day and I think if I make all the effort to get there I like to spend a little time. So I figure with 1 day Ljublana, 3 days Zadar, 2 days Plitvice Lakes, 1 day Zagreb I would want to have a few more days. Budapest, now that's a place I know a little about and you are a solid 2 days short. I know excellent accommodations here.
Vienna, the end of your trip. Nope, I personally don't much care for Vienna so I would put those days into Budapest, buy an open jaw ticket and return home from Budapest as it is an excellent place to enjoy the beauty and unwind after touring the world.

Thank you both for taking the time to reply. I have decided to drop Croatia this trip and concentrate on Austria, Czech Rep and Hungary. I will spend more time in Budapest, Cesky K and the Salzkellergut area of Austria. I really appreciate your assistance, Cheers Jim