Just an update, after all my apps and settings and updates and such. My OS install size is 11gb. I did disable Restore, Hibernation and Pagefile but i'm really surprised to see it this small.
As far as performance, the boot time is nice but i never reboot and just put to s3 sleep. Media Center does seem more zippy but i dont really see the performance benefits that everyone is speaking of, maybe because i'm have nothing to install like games and such.
When i open things like computer and control panel it may be 1 or 2 seconds faster. Not sure if this is worth it considering how fast the prices are dropping recently. I may re-buy and do a rebuild in the fall.
In any case you guys taught me a lot and i learned a lot through the process so thanks!