Owner for 15 months, R1150GS for 4 years before that, and still believe there is nothing on the market to compare with the R1200GS.
Recently had a long test ride on the R1200ST and loved the extra power, gearing more suited to on road work, and what seemed like an improvement in the gearbox. But still wouldn't swap the GS.
Also had a 90 minute ride on the K1200R, absolutely awesome, sufficient torque to make the gearbox redundant, comfortable riding position, superb road bike, but again, wouldn't swap the GS.
Happy? yeah, you could say that.