F800GS vs the other GSs...my view
Well, having spent a few hours on the earlier 1100 and 1150GS machines, and then owning an 05 GS, then an 06, 07 and now 08 GS Adventure (the 07 got traded for another Beemer), so now my spouse and 'share' the Adventure and the F800GS. However, since getting the 8GS in early Oct, I have pretty much lived on it, roads or no roads.
As a former KLR owner and having raced and owned a few dirt machines in the past, I can state that the 8GS holds up extremely well to any and all machines, past and present. When compared to many of them, it is the superior machine.
I owned an F800ST for a year (traded early in 08 given the pending, then delayed arrival of the 8GS), so I had no concerns over the motor, and the 8GS is actually 15 hp stronger, which is very much noticeable, and useable.
The two biggest pluses of the 8GS is its size and weight, and versatility. I had some concerns over the 21inch wheel on the road at speed, and to some degree, still do - the winds will impact slightly, but its not a major issue. For long distance touring, I still believe the 1150 and 1200 models provide more stability and for many, more comfort, especially for two-up or heavy load duties.
But, for single rider duties, with all the luggage options available already for the 8GS, I will have no hesitation in loading it up and pointing it anywhere that the 1200s have, or would have gone, pavement or otherwise.
The 8GS is very light, and even adding a good load doesn't make it unstable or slow (trust me) and when the dirt gets loose and the rocks bigger, that 21in wheel, light weight and dirt-bike characteristics of the 8GS will come to the fore, quickly. The 8GS is a hoot on the road (almost as much fun as my now departed Multistrada) and off road, its just a slightly 'bigger' dirt bike.
My fuel consumption average is close to 60mpg (Imperial gallon), the Scott Oiler takes care of the big long chain that has not yet required adjustment after 3500kms and that has been that.
I put on the large BMW skid plate (probably the best and widely available, at least up here), a SW-Motech Quick Release rack that lets me use GIVI or SHAD top-case adapters or a wide rack for the BIG duffel bags. A set of the GIVI engine guards went on quickly and work well, and provide convenient mounting points for other planned farkles.
A couple of RAM mounts host the GPS and the cameras and that is about it right now. Next up, probably, is a set of removable side pannier brackets, so I can use either soft or hard luggage, when needed. If not travelling distances, the machine stays stripped for the hard-core off-road stuff. Oh yeh, going to get either a BMW Touring Shield or other after-market item for the longer trips... So far, the stock seat has proven just fine, a sheepskin helps for a full day of riding.
Complaints, none yet...I just think of it as the 'smaller' but more capable member of the GS clan.
One is never enough...2014 F800GS Adventure Launch Edition and now, a 2014 R1200GSW in minimal Red, needing farkling. What, only two...the search continues for something else.