[CentOS] Running SELinux necessary for the average user?

I'm wondering because it seems to be slowing my machine down considerably
under CentOS 5. Especially the daemon they include to monitor SELinux and
the program that attaches to it. I tried opening this earlier and it just
sat there spinning.

I want the knowledge that my machine is secure and safe. But I'm wondering
if the price is worth it. Is it necessary for my machine to be fairly
secure?

Preston