I would pay attention to the Final drive (Diff) or as users on the forum refer to the "FD". BMW claimed it to be "lifetime maintenance free", however, personal experience has revealed, unless the gear oil in the FD has come from Hogwarts and bear the signature of Harry Potter this is but a fairy tale. The oil in the FD needs to be changed at every alternate oil change (20000Km). Have a look at what my FD look like.. 75000Km on the ODO.. http://youtu.be/NhkM1OCIJ4w
the movement should be smooth. Failure of the FD will result in catastrophic failure of the FD, drive shaft and engine. Should you be fortunate to survive- you will end up with a very expensive paper weight.
The oil feeder hole to the clutch is 1mm bore, once the gasket is placed it reduces the feeder hole to 0.5mm which results in not enough oil being fed to the bearings in on the clutch shaft, this will result in clutch bearing failure. These bearings can only be bought from the agents, a costly and labour intensive exercise. Do not think of increasing the dia of the hole, this is most certainly not an option. Rather cut the gasket slightly bigger to ensure the 1mm is maintained.
Cam chain should be done at every 70000Km- 90000Km.
The K1200's do not have hydraulic lifters, this valve seating needs to be adjusted when you do the Cam chain.
Do not skip services, ensure that oil changes are done regularly- the saying is "Oil is cheaper than mechanics" truly rings true on any
For the rest, you are about to embark on a AWESOME machine. HUGE power, excellent riding potential, safe (as safe as the rider rides it), ABS, the ESA is fantastic on long rides- not tiring at all. (I travelled 1600km and didn't feel like I was born and grew up on the bike) Pillion seating is excellent (Wife doesn't complain about her knees- She did howl in my ears with the GSXR K6 1000) The bike is very well balanced and steering is fantastic.
A aftermarket exhaust and sport air filters make the world of difference and you will not regret it. It is most certainly worth investing.
These are just some of the experiences I have had since I have had my bike.
I have found loads of tips and answers from this site.
Happy & safe biking.