I ran TFC, it cleaned a little more stuff, my available space is now up to 12.6gb. I'm going to hold off on turning off system restore as I have plenty of space now. My main issue was with space "getting eaten" with no rhyme or reason to it. I guess for now I'll see if I end the day with around 12.6gb still available, or if I notice it changing during the day. In any event, the machine sure seems to be running faster.