I did over 40,000 on my 2004 1200GS before selling it in 2006 (about 25 months).
The warranty work over the period was (as far as I can remember)
Final drive - leaking
Clutch - spline worn (my fault apparently
)
Front cover - corrosion
It went through a set of rear brake pads every service initially before the pads were improved. Can't remember if the front pads were ever changed.
It was a bit thirsty for oil.
Tyres - always Tourance - usually 8k at the rear and 12k at the front.
Headlight bulbs - 6 or 7, includes dipped and full beam.
Crashed once when 2 weeks old - stupid woman (tautism?) ran into the side of me on a roundabout. Low speed, very light damage, she accepted responsibility (several witnesses so she had little choice) and I went to the lakes the next day.
Full service history at Motorrad Central.
Vario top-box which rarely, if ever, was taken off the bike. The top box never leaked or fell off, even though the bike was routinely power washed with the top-box fitted. Vario panniers used infrequently - I didn't like the left hand one as the liner bag really didn't fit properly. The "extra" spaces in the left hand one were handy for velcroing in first-aid kit, bottle of oil (see above), cargo straps, etc.
The first list sounds dramatic when I read it back but none of it ever caused me any problems nor detracted from my, huge, enjoyment of the bike.
I swapped it for an Adventure which is different but not necessarily better, or worse.