I just tested the rectangle test again, this time on a large page (96"x36"), which was completely filled with objects and diagram components (the drawing itself is about 2.5MB w/ no background or other large graphics other than rectangles to designate areas).
Only if I made the rectangle over about 80% the size of the page as there any delay, and even then the delay for moving the rectangle was perhaps 2 seconds at the max, and it "snapped" between locations, you couldn't see the lines drawing or anything. In other tests, if I grabbed a 50+ small objects on the page and moved them, they move almost instantly, in both cases it's about the same performance I would expect on my PC.
Interesting that we are seeing such a different performance, especially since we are both running C2D's and mine is a 2.9ghz vs. your 3ghz. There are other factors, such as the RAM/FSB speed and video card, and perhaps OS sub-version.
Here are some notes about my configuration:
My Visio bottle is a WinXP bottle, graphics settings are default in WineCFG (Allow the window manager to decorate/control the windows is checked, and vertex shader is set to hardware and pixel shader box are checked).
My Mac:
I'm running Snow Leopard 10.6.2, 4GB RAM, 2.9Ghz C2D, and right now I'm running on my high powered video card (9600GT), now that I think about it I can switch to my other video card (9400M) and perform the test again to see if it's video card speed related. I'll do that and post a update.