As for the BMW reliability, i have done my research and a few years ago i would have agreed.
I'm afraid your actually incorrect the previous twin cam engine bikes are the best, especially the twin cam gs.
When it comes to reliability i take it you no all the problems that the new water cooled gs has !
1-Corrosion issues on brand new bikes, resulting in replacement engines due to corrosion after 2k
2-Faulty ESA units, resulting in harsh suspension.
3-faulty switch gear.
4-cam chain lock up, results in replacement engine.
5-early 13 bikes panniers did not fit, BMW bodge was to fit penny washer under the rear hangers, however some bikes had to have new rear subframes.
6-early 13 bikes frames with misaligned steering.
7-rear brake pads down to metal in 2k, still ongoing problem
8-rough clunking gearbox even after several fixes its still the same.
9-brand new bikes leaking water out of water pump hole, one particular bike had to have a new engine because of this and the reason why they could not fix it was the crank case was porous.
10- clutch drag .
Thats just 10 issues and there's plenty more problems as well.
Reason why ! Because 70% of the manufacturing of components on the new generation bikes especially the GS water cooled are sourced from china .
You will have to be very brave buying into the gs wc blind folded.