Will a Performance upgrade occur after clean install?

Question

I currently have a three yr old MBP that had Leopard on it and was upgraded to Snow Leopard.  I also upgraded the hard drive.  Over the years, I have lots of programs and files and have a complete TM backup.  I am thinking its time for some system clean up and was wondering if I do an ease and fresh install of Snow Leopard and then restore the TM data, would I see better performance that would make this excersie worth it?  Was also thinking to so this at the time of Lion release.  I know its time consuming and would like to get rid of the spinning beach balls that I tend to get and thinking that since its been a machine that has been a workhorse with two upgrades its time. 
Thanks
jf

Answer 1

Yes, a fresh install will make your machine perform much better, but you should do a complete fresh install of programs and everything for best results, no TM.
What you should do is use a regular HFS+ Journaled external drive and move your files there for safekeeping.
Then c boot off the installer disk that came with your computer, use Disk Utility to Erase and format your drive HFS+ journaled and reinstall OS X.
Setup the machine with the same user and hard drive name as before (you'll see why later)
Then use the Snow Leopard upgrade, then do a Software update to get to 10.6.8
Doing it this way gets your free iLife that came with the computer on the 10.5 disks.
Next install your applications from fresh sources, then finally your files from backup.
When you replace your entire iTunes Folder, because you used the same user and hard drive name as before, all your playlists and music location in iTunes will work. It's because you matched the pathname.
That's it, it's really not that hard, it's just that you have to maintain the source of all your installed programs and any product keys you have.
Once your done setting this up, consider cloning your entire boot drive (no filevault or bootcamp) to a another, HFS+ journaled formatted drive using Carbon Copy Cloner (donationware) or Superduper (partial payware)
A clone of your boot drive is "hold the option key when booting" selectable as a boot drive.
However, you should ALSO use TimeMachine too, to gain the benefits of that, but each clone/TM/backup shoudl be on their own seperate drive, so you get the protection that your vital data is not all on one drive.
It's more work, but you get a highly clean and optimized system.
When OS X Lion comes out, you upgrade from the MacAppStore and then check for a update for CCC.
Good Luck.