Heidelberg or Rothenburg

Heidelburg and Rothenburg are pretty far apart. Are you sure you want to do them as consecutive stops?

Personally I wasn't hugely keen on Heidelburg but that's because I'm not a great fan of eighteenth century Classical architecture. It's all pretty homogeneous in that style.

answering a different question, Rothenburg is very nice, but not worth two whole days.

I don't see very much difference in the choices you've presented. Going to R'burg on Day 1 would mean a longer driving day - but only you know where Day 1 begins and whether that would be too much car time for one day. Do you prefer 2 nights at any given place, or is a 1-night stop no biggie? As to character and perhaps evening activities... there ARE some differences... Heidelberg is no doubt livelier and a somewhat more authentically German place, as it's a normal town of diverse enterprises, with a larger population. Rothenburg is disproportionately populated by tourists and tourist-industry innkeepers and shopkeepers. Perhaps your trip will take you to other similarly-normal places like Heidelberg - but if not, you might want to spend the night there for the experience; 2 nights in R'burg are not necessary, nor is more than one full day, IMO. But if you are spending only 2 nights in Germany, then a 3rd night in H'berg would surely be worthwhile for most people, I think. I assume you've examined the sightseeing options between H'berg and R'burg and concluded they are minimal, and you could just as easily drive straight through to R'burg. If you have not done so, then take a look more closely - you might find you need some day time hours in places on the way and will opt for a night in H'berg.

We enjoy both Heidelberg and Rothenburg, finding both of them a worthy stop.

We like the walk to the castle and around grounds in Heidelberg, and find it worth a day.

In Rothenburg, we enjoy not only the city itself but also a walk in the Tauber Valley below it. We always spend two nights.

https://mcchelsea.smugmug.com/Germany-April-2016/Walk-into-the-Tauber-Valley/

https://mcchelsea.smugmug.com/Germany-April-2016/Detwang-2016/i-NjFgX9k

For my taste you can not go wrong with either place, or both in this case.

Another attraction of Heidelberg is the nearby Schloss Schwetzingen with beautiful baroque gardens. An half-hourly bus (# 717) brings you there from the main station (Hauptbahnhof) in Heidelberg in some 30 minutes.

We spent 3 days in Rothenburg during our visit last month and I loved it!! From the people, restaurants, shopping and history I couldn't get enough.. the town is simply amazing and def the highlight our our trip.. best time is early morning or late afternoon when the crowds leave. Two awesome restuarants to try are Zur Holl and Alter Keller!! You won't be disappointed.. :)

Thank you all for your comments! Very helpful! I have another question, but I will start a new discussion thread!