Retro AS-1 is simply incredible. After installation, it was a piece of cake to integrate it with MOTU's Digital Performer 2.4. I select it just like any other FreeMidi device. It works seamlessly! 16 part multi-timberal and polyphony is limited only by CPU, memory etc,. It also can be configured to work under OMS according to Bitheadz.
Oh ya, the sounds... All I can say id=s they're great. Truly impressive fatness and unlimited wierdness can be created very easily. Sound quality depends on what your Mac external speaker jack connects to, but I must admit that even with my Cheapo LabTecs the sounds rock! Latest version supports AudioMedia cards. Bitheadz include tons of patches (1000?) to help get you started. Manual is in PDF format so you'll have tp print it out for hard copy (about 160 pages). Good manual by the way.
Download the demo and see for yourself at www.bitheadz.com!!