Hi. I have the 9000 Pro and most of the expansion boards (about to buy the DX one). Here's some good review sites on the boards:
http://www.computermusic.co.uk/reviews/plg150pf/plg150pf.asp http://www.computermusic.co.uk/reviews/plg150an/plg150an.asp

Most reviews I have seen are using an S80 or the Yamaha sound card as the host for the cards so no one has done a good review of what it's like using the 9000 Pro with these cards. Personally, I truly LOVE my PLG150-PF card but that's because I really wanted a great acoustic piano sound without eating up the polyphony of the 9000 Pro. That's the real benefit of the cards is that you not only add new sounds but added polphony (64 notes in the case of the PF, the most of all the expansion cards). I couldn't live without my piano expansion board anymore. I like the AN card a lot also but I really don't have much of a use for it so it's about to go into storage (it only added 5 notes of polyphony anyway but it does have some truly fat analog sounds and it is easy to program). The VL card is ok but not nearly as good as I expected, which may be why it's the cheapest expansion card, plus it is monophonic and seems to be geared more for the wind controller user. I am after the killer electric piano sound now and I didn't like the electric pianos provided by the PF card. The DX card adds another 16 notes of polyphony and the demos sound like what I'm after, so that's my next purchase. If anyone is interested in buying my barely used AN and/or VL cards, make me an offer and email to jimeshleman@hotmail.com.


BTW: the Yamaha-Europe website is listing two new expansion cards which I haven't seen in the US yet, one for drums and another for percussion sounds: http://www.yamaha-europe.com/yamaha_euro..._plugin_boards/


Esh

http://www.mp3.com/esh