Great thread, very informative.
I guess I just want to get my $0.02 in as far as my experience with SU and hardware. I'm an old fart that love to game at times and get into some Photoshop and Illustrator but love to create in 3D models in SU. So about a year ago I built a rig that would let me play and work when I needed to.
Granted I've experienced the glitches early on as I was using ATI cards at the time as a matter of fact I'm still using a ATI/AMD GPU setup to this day. I think since Catalyst 9.5 I have not experience any bugs or glitches in fact it's been very smooth for me. I may not run those mega file like you pro but I've had my share of almost mega file with very smooth navigations.
These are the specs of my old humble play/work rig...
MB: Asus POG Rampage II Extreme
CPU: Intel i7 920 D0 @ 4.2GHz
RAM: Corsair Dominator GT (12GB) 2065mhz
GPU: XFX ATI Radeon HD 6990, 4GB, DDR5 (UPDATED 12-11-11)
Optical Drive: Pioneer BDC-2202B Blu-Ray
HD Primary: Western Digital VelciRaptor 300GB
HD Storage: Seagate Barracuda 7200.12 1TB (x4)
OS: Windows 7 64Bit, SketchUp 8 Pro
Monitors: Samsung 245T 24" (x3)
Since I game using Eyefinity technology here is a shot of SketchUp at a resolution of 5760x1200. Even at this resolution SU is very smooth.
Hope you guys like it and if you have any question fire away.