@Bobby- I've been tempted, but haven't tried out the Windows 7 RC. I do have 2 copies on order, though, so I'm a few months away.

When I first installed Fences, I couldn't decide whether it slowed my system down or not. I'm pretty obsessive about stuff like that, so really tried to watch for it. Now that I've used it for a few months, I definitely don't notice any speed issues. My system is just over a year old (3.0 Core 2 dual core, 4 gigs of RAM, 64 bit).