The new GS is liquid cooled. The BMW's hold their value really well, kinda like a HD. The Bimmers have some way cool tech on them, paraleve and telever suspension. But a guy in my club had three transmissions replaced in his Boxer Cup Replica all under warranty. The third transmission BMW sent downa tech with the new tranny in his car and he installed it. I had a FZ1 that I put 30k miles on it with zero issues. At 25k miles the valves were still within specs.
I think the GS is a nice bike but the cost and maintance and reliability puts me off. Also the Yamaha seems to be very competiantent and is less expensive and of course should be more reliable. The only down side for me is as I mentoned, other than HD and BMW, these bikes seem to depreciate pretty quick. Really not an issue for me since I tend to keep a bike for 5~8 years.