Coming from the KTM-side the Adventure 990 was a natural option. Rented one for a weekend from my KTM dealer and liked it very, very much. But after having watched the "Long way round" and KTMs very poor showing there, I also got a test ride on the F800GS and ordered one right afterwards. What really made the deal for me was the offroad capabilities of the F800GS. With the Adventure I felt a lot of respect for the weight of the bike as soon as I left the pavement - with the F800GS I was drifting on the gravel roads in no time and even on a steep, slippery dirt track I had no problems except when I turned aroud and forgot to disable the ABS on the downhill
Add less weight, considerably less service costs, better fuel mileage (less weight for same distance) and comparably power output and the decision was actually an easy one. BMW dealer was very nice also and I was able to get a bike right away. Love it! For me the F800GS is definately the better Adventure
A 690 Adventure would have been a serious contender though, but since KTM is taking its time and after reading about the EFI problems on several 690SMs (stalling) the 690 was out of the picture.