oh cool ... didn't think about Bratislava. I know Vienna is by far the most expensive city of the 3 and I also think there will be plenty to see in Budapest and Prague, so I can probably make the Vienna stop shorter.
How did you commute from city to city? Did you drive or took train / plane?
I also find there's almost no direct flight to Budapest / Prague, so I most likely have to transit through Amsterdam or Lisbon. I may spend a day in Amsterdam (took a trip to Lisbon with wife just 2 years ago, but she's never been to Amsterdam) and that makes my trip in other 3 cities even shorter.
I didn't get to Bratislava but have been told, if you go to Prague, no need to go to Bratislava as it is basically a poor version of Prague.
I did Prague, Budapest and Vienna a couple of years ago. Spend the majority of your time in Vienna if you can. I took a day trip out to Salzburg from Vienna.
Prague is nice but in reality, it is only a small part that is really worth seeing.
Budapest is nice, but far poorer and few speak English.