Thanks for those with a few minutes to share your thoughts. First, to let you know, I downloaded the trial and was too busy at the time to do much with it for the 30 day trial.
I can get the upgrade if it improves the editing experience. I am on a Mac Book Pro i7 2.0 intel quad core, 4 gigs ram , summer 2011. CS5.5 seems to run just fine on my computer.
Thanks again