I hadn't even heard of it until this thread so i went and downloaded it. Seems to be working pretty well. I turned the activity/process management to aggressive also. Sped up the animations. Enabled compatability mode (for no reason really). Everything seemed cool then it crashed and rebooted and when it came back up it kept defaulting in landscape mode and I'd have to open and close the slider to get it to go to portrait. I restarted the phone again and now everything seems fine, although I turned compatability mode off. Everything seems good now. Phone's quite a bit snappier with the animations sped up.
Something important to note for those that use spare parts. Spare parts is not really an app per say. It is an app but all it does is let you access options that are already in the system that you normally cannot access. If you have problems DO NOT uninstall spare parts first.
You must first revert the changes you made in spare parts THEN you can uninstall. if you uninstall first all your changes that you made that were messing your system up will still be switched on.