Machetero, I think I can answer your question for you...

If you already think the S910 is a very nice arranger, you aren't going to like the BK. It's a Roland. They are NEVER going to sound or work like Yamaha's. As well they shouldn't. There ARE still a bunch of us that LIKE that 'sound', the punchy live aspect (I play in live bands all the time, and no way a Yamaha would cut through a real drummer!), and if I wanted a Yamaha type sound, I would get a Yamaha, not hope that Roland make something JUST like a Yamaha!

Trouble is, of course, if you really NEED a module, it's the only affordable game in town. Yamaha are about as likely to bring out a module as they are a 76 Tyros!

Go and listen to the BK, by all means. But I'll save you the trouble of thinking about buying it... If you like a PSR S910, get one of those!