Hi Jody
I'm pleased you are reviewing sketchup! It's a great program, and I can't wait for the new improved version!
Largest file I have created is 59.8MB, using over 10,000 2D plants with textures. It takes about 20 minutes to render shadows on my Mac Pro 8-core. I too would love to see SU using more of my available power!
One of the biggest issues I find is faces - especially large ones made with circles/arcs. This constantly causes frustration and often crashing, when trying to make a face re-establish.
For LO the biggest file I have is 298 MB, which contains several copies of the 59.8MB SU document from above, with various annotations, etc. It loads relatively quickly, but is slow to change pages (up to 2 minutes), even on my big machine.
If you are really looking to put out new version, I beg you to read SU and LO wishlists - there are so many things we'd love to have - and personally, I'd pay for an upgrade if they had them.
Thanks.
Shannon (Landscape Architect)