Just got Mach 5. Positive pre-installation impressions: It works with OS9 and OSX (10.2). (I thought it was only going to work in X!) Built-in Spectral Analyzer and tuner. Looks like you do pretty much everything in ONE window. Sweetwater Sound included 4 pieces of candy in the box. Unexpected baaaadddd news: It's got a USB iLok SmartKey (otherwise known as a "dongle", perhaps?) that must be plugged into a USB port for the program to run. I don't know if you can authorize more than one Mac or more than one OS. Onward through the fog! Included is a Soundbank DVD with over 4.3 GB of samples, which appears to be a "Greatest Hits" collection from Ultimate Soundbank (http://www.usbsounds.com/). No suprise... Mach 5 uses their UVI engine. Most of the sounds are rhythm section... LOTS of drums & percussion. There are a couple of 192 kHz instruments and a surround-sampled pipe organ. Time to load up a few Gigasample discs and see what happens! Scott Jacob Loehr