It does very well on a 32 bit system. I film bands live, I only add small filler clips and have a external audio file that I sync. Nothing too crazy. In this video I shot this weekend (league of Liars - YouTube) I had zero issues with the program. It ran smooth. Think of the video just as an example, for anyone wondering what you can easily do with a 32 bit system.
Regarding performance, for anyone having issues, rendering video clips as you go really helps my system out and there are settings that can effect your rendering speed. I don't know enough in detail to guide anyone through those steps, but there are people such as A.T. Romano in the forums that be of much greater assistance.