Ive ridden an 04 BMW1150 GS and a 2016 BMW r1200rt. Both bikes surprised me with their light handling. Parked beside my Triumph Thrux they are huge, but on the roll they aren't half bad. Vibration was quite severe with both bikes, especially under acceleration.
Interestingly, the 1150 is rated about 80 hp and the RT is 110 with weights similar. The RT might have had slightly more acceleration right in the last 500 rpm, but not much.
Going by the numbers it should have been much stronger than the older bike, but the reality was that they were about the same, neither one overly peppy. After the 1200 rt owner fitted a performance exhaust, he asked to run the 1200 against the 1200 Triumph for fun ( and hopefully a win) Weight with riders is about the same as he is about 175 lb to my 230 and BMW claims 505 lb for the RT.
With 110 HP to 97 the BMW should have prevailed,but it wasn't even close, the BMW was left in the dust at every roll on, no matter what speed.
Shows how numbers on paper don't always translate into performance.
The RT had a real problem with slow speed lurching, horrible in town traffic or putting thru a busy parking lot. It's a fueling problem combined with driveline slack in the shaft drive, very common with that version RT.
Like all brands and models, the people who own them love them.