Hi Mike, I have Perfect Photo Suite 7 and used it a few times with no issues on my 2008 MacBook. I still do 90% of my processing in Aperture 3 (apple software), but everything I use Perfect Photo for seems to work well. I initially bought it so I could work with layers (Aperture 3 can't), but have experimented with the other areas of it as well.
I keep promising myself to make time and work out how to use it better but work keeps getting in the way....
Hope this helps a bit, a little vague as I haven't used it extensively sorry.