THe guy above me is right. The GM [Organ 3] is probably the best B#-like organ on a stock JV/XP. I'd recommend learning how to man your machine. Learn to tweak sounds. You CAN get some very convinvcing sounds if you know how to get in deep.
As for the rotary speaker effect, not all of the stock B3's (in the XP) use this effect. Some use ALTERNATE PANNING and other tricks to get the sound to move from both ears. the waveforms themselves are not bad, but you have to thank Roland for thinking of this so you don't have to use the ROTARY effect in one of your performances, you could use a different effect instead.
You should either consider the the [60&70's], [Session] or the [Experience II] boards. They all have some great B3's.
Also, the Rotary's built into Rolands JV/XP-like SC880 are some of THE best that I've heard, and some have the ROTARY effect built in!
Just my 0.02!
The Infamous EPU.