Yeah, reformat on a single HD is a pain, plus windows gets clogged over time. Its just good practice in my view.
I don't mean to hijack this thread, but its relevant. With the above in mind, I was planning a build with 2 harddisks. The original plan was 2x seagate barracuda 320GB 7200.10, one for OS one for other goof. As for the OS HD, is it really worth bothering with a WD 74GB 10000rpm? It would cost a bit more than a 320GB seagate? what about an 80GB seagate, would that be sufficient? Is there any gain from using two identical hard disks, or does it not matter?