According to my experience you should be a bit careful with packing the F 650 GS together with KLR, DR and the like for the following reasons:
The F 650 GS is set up quite similar to the R1200GS (just lighter :-)
The suspensions are not happy on rough dirt roads. A bit too hard, not enough negative travel (because of not enough overall travel) The whole bike is set up as a middle class tarmac tourer with top speed stability for the European market. The small front wheel makes availability of knobblies / semiknobblies a problem.
The F 650 Dakar is a bit better with regards to tire availability but also loses due to hard springing and damping. The bike is very high and heavy (without gimmicks it's already heavier than the army tank KLR650).
Both BMW 650 GS and Dakar are too showy for rough tracks. They look better than a DR or KLR in front of a café but they also break a lot easier if you dump them down a slope.
The KLR gets criticism for being soft but as long as it's not heavily loaded this gives you good performance and control on bad terrain. Both DR and KLR pay for dirt road performance with less high speed stability on tarmac but I've been throgh some hectic stuff like soft sand, soaked clay roads, rivers and rocky scrambles with them which would have been very nasty with one of the 650 BMW's.
I did not say get only a DR650. Obviously the combination DR650 + BMW R1200GS would be very nice :-)