These cities are very scenic (at least on the web) and seem to have a lot in common, even thought they are in different countries. How do they stack up against each other for a short stay in the summer? If you could choose only one, which would it be and why?
I meant to type "it" meaning Bolzano. Quirky iPad. I have corrected it now. Lots of charming places to stayin G-P, from little guesthouses to nice hotels. We will be there in September and I am looking forward to it!
My choice would be GaP, hands down. Innsbruck and Bolzano are sort of similar, but GaP is completely different. The first two are fairly large, rather industrialized cities situated in broad valleys surrounded by the Alps. GaP is primarily a resort town. The mountains and hiking trails are much more accessible. Innsbruck and Bolzano do have historic districts, but most the cities are fairly modern and not particularly charming. GaP, on the other hand, is mostly (but not exclusively) traditional Alpine Bavarian architecture.
Ditto what Tom said. I found Innsbruck to be a huge disappointment. Bolzano has the Ice Man Museum but not much else of interest. An alternative to these three would be one of the villages in either the Zillertal or Stubaital which are both south of Innsbruck.
Funny-I read the question but turned away to attend to my cooking before reading the responses. While stirring the eggs, I formulated my answer, which was " Garmisch, hands down.". But Tom said it first. Not only is it a nice and very hospitable small town, there is fantastic hiking there. We happily go for 3 nights there. Bolzano is a one-night stopmonnour way to or from the Dolomites. That is plenty. it is hot and humid in that valley, and lodging there is inexplicably expensive. Innsbruck? Meh.
GP seems to be the clear favorite. What is MIT? Mittenwald?
It depends on what you are looking for. Gramisch-Parternkirchen wins, by far and large, if you like panoramic views high up in the Alps, as the Zugspitze is probably one of the top 3 observation decks in the Alps, allowing ample views on a 360-grade basis. Innsbruck is a better option is hopping from one mountain to another is your thing. Bolzano works better as a base to explore by car nearby places, and has the best culinary of those 3.