The K1200GT model had a serious problem with its air box and driveability. Many folks never could get their bike running properly. If you have it (or any newer K bike) serviced at the dealer it is the second most expensive BMW to have serviced behind the K1200LT series. It eats tires like any other K bike. The above advice to get a K1300S is as good as gold. But be prepared for maintenance costs or do the work yourself. Any 09 through 15 would be wonderful. If you can't ride it for 20 minutes don't buy it. I know this makes it difficult but work it out.
I have an acquaintance who owned two of them, his wife's was ok but his was in the shop all the time with no good outcomes. He sold them both for FJR's.
Mount Vernon, WA.
tire guy, I'll mount your tires.