I don't know anything about the BMW, but if you want to ride hiway all day, consider the KLR or Suzuki DL650.

The AMA D/S rides are just trail rides, not competitive. That doesn't stop people from riding like idiots, bumping into you and cutting you off to get around you if they get in their way. I've been to the AMA D/S rides at Sam Houston National Forest, Terlingua, and New Blaine Arkansas. I would not want to be on something as big as a KLR on the Sam Houston or Arkansas rides. Terlingua would be a good KLR ride. But I've seen big guys with long legs really ride the snot out of a KLR, so if you're a big ol' boy, go for it.