It works decent, Although I use cineform to convert my files before importing into cs4. I had less problems with cs3, but maybe thats just me. Cs4 seems to crash a lot. God I wish I had a mac with final cut. lol
If you can get your hands on Premiere Pro CS5, I'd highly recommend springing for that software. You can edit the t2I native footage on 3.0 ghz dual core setup in real time without transcoding.
Online-offline processes are pretty scary the first time you do them.