When I ride my favorite roads in the Alps, my best choice is a XBR500: I prefer the small roads with plenty of bends, typically South Tyrol, Trentino, Lombardia. However, the Alps are much more than that. Every year the largest motorcycle magazine in Europe (MOTORRAD) is doing a large test of new motorcycles in the Alps, called the Alpenmasters. There is one bike that won most competitions: the GS. This is not a surprise, it is probably the best allrounder and compromise for these roads. If I could choose, I’d take one. Or maybe a new Africa Twin. Because there is one asset that these bikes have: apart from the on-road performance, gravel roads pose no problem. Yes, there will be gravel roads. Not a must, but there will be great, classic gravel roads at all difficulty levels and for all tastes.
But: you can ride the ABR with any bike.