I would say, that your RAM usage is not the issue, but you would need to edit in some more measurements about what is slow (or make the detailed measurements in the first place) and look at perhaps network latency (web pages take a while to paint), network bandwidth (iTunes movies take hours to download instead of minutes), or CPU perhaps.
In the RAM snapshot, the system looks to be used lightly, due to a small amount of inactive RAM and the large amount of free memory. Over time, if your programs need more than half the RAM for active and wired, you would see a speed up when switching between seldom used apps if you doubled your RAM so that rather than releasing memory, the system would build up a larger cache of "inactive" memory, but that's just speculation.
Why not pick one or two things that seem slow to you and make 10 measurements on how long they take. At that point you can ask a more pointed question or perform the restore and re-test the speed to see if your change made any difference.