I just bought 2 of the DS2416s 
  from zZounds... although one is a gift for my brother.
  For those of you not 
  familiar with this card... When installed inside a personal computer, the 
  DS2416 digital mixing card offers the mixing power of the successful Yamaha 
  02R digital mixer plus 16 tracks of hard disk recording with up to 32-bit 
  resolution. The DSP Factory appears to 
  be a comprehensive digital 
  mixing and recording system, providing full-time 24-channel digital mixing and 
  two of Yamaha's top-quality digital effects processors, without having to rely 
  on the computer's internal processing power. 
  Additionally, the DS2416 card includes an audio-streaming 
  engine which provides 8 tracks of simultaneous recording to, and 16 tracks 
  playback from, the computer's disk drive. I'm hoping this feature will give me 
  greater success than I had with computer-based composition 
  previously.
  The card isn't flawless - it only supports a 33 MHz bus speed 
  and there's no lightpipe, for example, but it's attractive in many ways... 
  those of you who may be in the market for a card might consider it...
  And besides, there's a deal to be had right now. Like you, I had an email flyer this 
  week from zZounds and they're blowing out the DS2416 with a separate digital 
  I/O interface card (that's two cards), with a MSRP of $1295... for only $299! 
  It was something of an impulse buy for me - I didn't think they would last 
  long at that price, although they are still in stock over there. Sweetwater 
  and Musician's Friend are each still selling the card for $600. So, I bought 
  two.
  You can read about the zZounds deal here (there are 
  two):
  http://www.zzounds.com/love.music?p=p.YAMDS2416AX16AT&z=1022981872889
  http://www.zzounds.com/love.music?p=p.YAMDS2416AX44&a=em032701
  Best bet for info though is the Yamaha site, where you'll have 
  to do a search for the DS2416. The brochure and Owner's Manual are worth 
  perusing. On the Yamaha site, you'll see 
  references to the sequencers supported... they've got some big names in 
  there.
  For reviews, check out:
  http://www.computermusic.co.uk/reviews/h2hsoundcards2/ds2416.asp
  http://www.yamaha.com/proaudio/SHOWCASE/REVIEWS/review23.htm
  Best 
  of luck to you,
  Kevin