I've never owned one, but have test rode them. A guy I ride with has the cruiser version. I've heard they are maintenance pigs, but only from non owners and consider the shit you hear about Ducs from non owners .
They are heavy and down on power, especially when you add in the losses crank to wheel (about 15%) from a shaft drive, but hp isn't as crucial on a fun bike for putting.
Also didn't mention the new Beemer F 800 ST or R 1200 R. The 800 ST is belt drive and R 1200R shaft. The suspension on the R will give you a very comfy ride, F 800 is comparable to the baby monster in price if you don't option it up. For that matter, the Buel Ulysses is a fun bike to ride, but definitely ends up in the shop a lot, according to some long term tests by the motorcycle rags.
You should be able to get test rides on any Beemer, most dealers offer them, also the Ducatis, and hopefully the MG.