I rode the Triumph 800 XC and bought the BMW. It has not surpassed the F800GS if you want to use it offroad. But the XC is a nice bike. Liked the engine better, hated the suspension.
Mine is a 2010 and they have gas tanks that split. Mine was replaced under warranty. The water pump leak was too. I also had some oil leak, like a cam cover or something. Don't remember, took the bike in for something else and they told me that it was fixed under warranty. All the defects were found and fixed by the dealer when visiting for other service. Nothing has left me stranded. 6500 miles and moderately abusive to it, its my primary offroad bike.
My advice is if you want to ride before 2015, buy what your gut tells you too. A look back through BMW history will show you that it takes them a LONG TIME to "remodel" and make changes. If you have a bike now that you like and you are currently enjoying some 2 wheel action, then waiting may not be such a bad idea.
'03 BMW F650GS
'10 BMW F800GS
'80 BMW R100S Cafe
'02 BMW R1150GS
'99 BMW R1100S