I've been standing at the BK-9 all day and trying all the styles and sounds. This keyboard is really good! In the previous models Roland hasn't done as good a job in voicing all the style parts. I especially like the use of guitar strumming in lots of the "live styles" and unplugged styles. The sounds are all top notch quality. I'm really liking the dual screens because it allows me to do things like look at lyrics and also be able to see all the sounds and important information without having to come out of the lyrics display as most of the other keyboards do. I've also gone into global parameters and fine tuned the functions I like rather than what Roland likes. I for one don't want the bass inversion light to come on every time I select a new performance, so I went into the global area and turned the lock "on" for this feature. I also wanted to be able to have just a drummer and not the whole band when I select a style and hit start. When I hold down the track mute button I can select what parts of the style will be heard when I turn this button on. From the factory, the Bass and Drum track are heard when mute is pushed. I added the bass to be muted and saved this as a global set up and now when I push track mute I only hear the drum tracks no matter what style I'm playing. It's very easy to learn how to use this keyboard.
I've also assigned .wav files to the 7 audio keys at the top of the keyboard and saved these on the USB drive so I can recall them whenever I like.
Even without the vocal harmonizer I think this keyboard is a winner. It's a lot less money than it's Korg and Ketron 76 key competitors and sounds in my opinion every bit as good.

I look foward to reading your reviews when you get a chance to get your hands on a BK9.