Something I found last night
Interesting topic, as I'd been noticing the same issue with saves and loads.
Quick saves were taking 5 to 10 seconds for me.
I'm running an Athlon 1.4 266, 512MB ram, Gf4 Ti4400 128, and playing at 1280x1024 with full options on. I was also running with 2x AA turned on.
Last night, I wanted to see the difference of having the Quincux (sic) AA on, and it seemed to be running slower than with 2xAA, so I exited and tried no AA for comparison.
With AA off, Quick saves became Instant!
Not sure how this ties in with the other issues you all have mentioned, but it's another version of what was changed to improve load/save times.