The biggest difference that you'll notice is that if you've ever rendered something once (say, for a RAM preview), then you'll never need to re-render it (such as for final export). That's because of the global performance cache.
See this for details:
There are a lot of other performance improvements from After Effects CS5 (10.0) to After Effects CC (12.0), but that's the really big one.
considering my workflow and rig, would more RAM do anything for rendering time? or does that really only come down to processing power, video card and Adobe's rendering engine in AE?
I also have the option of Production Premium CS6 through my university for $600. CC is $240 for the first year, no word on pricing afer that.
edit: reading a bit about Global Performance Cache, it looks like maybe more RAM would be good if I upgraded to either CS6 or CC?
RAM, CPU, and disk speed are the most important things. Only consider the GPU after you've taken care of those other things.
See this page for resources about making After Effects work faster: http://adobe.ly/eV2zE7
See this page for information about hardware for After Effects: http://adobe.ly/pRYOuk