Magma Chassis Decisions

[sinkrock]

I'm in the process of upgrading my rig and need some advice!

I'm going from a Dual 2Ghz G5 to a Mac Pro 8 core.

1. Will I see a huge increase in performance between machines? I obviously expect to see a marked difference - are many Mac Pro users using less TDM plugins and a lot more RTAS plugins in sessions?

2. I'm looking into buying a Magma chassis for my cards (HD3 Accel). Is anyone running a stable system with a Mac Pro and a 4 slot PCI4DRQ (I know this is unsupported!)? Is the only option the 6 slot PE6R4 chassis?

3. Based on replies to point 1, I'm even considering selling an Accel card and going down to HD2 Accel. Has anyone gone down this route? My sessions usually run up to 64 tracks and I'm using some MCDSP, SoundToys, Sonnox and Digi plugins. I'd only really be looking at running UltraChannel, Revibe, Smack and Impact on the Accel cards.

Thanks for your help!