Bachus,

The Sonic as Bill states is not limited to 4 VST's, it can do 16. Wersi's "Plug In Host" was setup so the average user could easily install and use four of their favorite VST's. Once installed, the system sees them as native. You simply place presets on any program keys/buttons you specify or scroll through the sounds as a set list. It's quite simple really.

You can load more than 4 VST's in the Abacus, Louvre, Verona, etc., but doing so requires you to load and run them from a different host rather than Wersi's built in host. This is more tricky to set up but not difficult for those saavy with computer based VST programs.

As with any VST based system, how many you can utilize at once is based upon CPU power and RAM. Programs like Omnishpere are memory and CPU hogs and can tax any high end system quickly. Don't expect to run multiple channels of Omnishpere, EW Strings, Hollywood Strings, BFD, and other memory intense programs at once. That isn't viable on any computer platform which is why major film composers dedicate a single computer to ine or two VST's. The fact Wersi allows you to integrate these VST's into OAS is a major plus.