white iMac Lion blues

I upgraded my 2.3ghz 3GB Ram 24" white iMac to Lion some time ago and Aperture and CS4 run very slowly with frequent crashes. I tried repairing permissions to no avail.

I still have Snow Leopard on my back up drive and am tempted to go back to it as things ran much better plus Word works.

I also have an Aperture Vault.

My questions are:

1) Should Lion work better and how hard would it be to accomplish this? Should I try a genius bar (long drive)?

2) If I go back to Snow Leopard how do I make my Aperture Library match my vault (as opposed to the other way around when I back it up)?

Thanks,
--
Russ