How hard is it to rent a car in Prague and return it in Vienna?
Anyone with any experience?

Check with autoreurope or Kemwel, but be aware that there are hefty cross-border fees.

I've wanted to it for our trip this October, but the fees seem unreasonable. Our alternative plan is to take the train to Chesky Krumlov, stay over night and the take the LOBO shuttle to Vienna. Seems cost effective, gives us time in CK and the route is a good use of time over a day trip on a tour bus from Prague to CK.

Ditto S

Thank you for your help. I checked car rentals and they are cost prohibitive when dropping off in another country. I think we will take the bus and the Lobo shuttle.