Thanks Andrew. I'll look into the 2-bus and see if it makes more of a difference or not.
Also, have you seen the UA video on Fatso? I believe the developer of Fatso worked with them and they even were able to take it one step further to fulfill the developers dream to have El Fatso. From the video, it seems UA nailed it pretty good.
Here's a bit about it:
"Endorsed and scrutinized for accuracy by designer Dave Derr of Empirical Labs, Universal Audio has painstakingly recreated the FATSO Jr. in this highly anticipated UAD Powered Plug-In, capturing the sonic nuances of the original hardware. Specifically, the FATSO is designed to musically integrate frequencies and transients — and increase the apparent volume of your source material — in the same way classic analog equipment does."
Here's the link to the vid.
http://www.uaudio.com/products/software/fatso/index.html
Jamie