you can change vst presets in live by changing the bank and program on the midi clip...
http://en.wikiaudio.org/Ableton_Live:MI ... am_changes
I have heard sets where this done before flawlessly but I could never get it to work without causing a hitch on my system.
I hope it works for you.
I've also broken down my set into multiple racks and used rack select on the clips. Then I just have those always loaded. Racks don't use so much cpu when they aren't in use. But be careful with this as overloading your pa with tons of vst's can start to create latency problems. Also, when they boot up from this state they can cause latency or glitches in your audio stream.
I think best is hybrid approach... a couple tracks with tons of racks and then rest audio tracks. Or get some hardware instead of vsts matthew jonson style.
i'd love to hear others experiences as well.
