Restoring with Time Machine because of sluggish performance

Hey guys,

I'm running Snow Leopard right now that I upgraded from Leopard a few months ago. Lately, it's been somewhat sluggish so I wanted to do a clean install of Snow Leopard. However, there are some programs and settings I didn't want to lose so I was thinking of performing a Time Machine backup and then using the Migration Assistant. However, if it just copies what I had on Time Machine back onto the clean Snow Leopard, how is that any different than what I had before? Is there a way to copy on specific applications back on?

Thanks!