I'm looking at two different Mac Pros on craigslist. Right now I'm running a 2.3Ghz Dual Core G5 with 6GB RAM. I know you can buy the quad core and then always upgrade the ram later, but i'm wondering which one is going to better as it is right now. I use a lot of plugins, and as many as 30-50 tracks in some songs. Here are the specs of each: 2x Xeon Dual Core 2.66GHz 15GB RAM 1.5TB+2TB+2x1TB HDDs or 2x Xeon Quad Core 2.66Ghz 5GB RAM 300GB HDD Both are the 2006 models and both are running OS X Lion Thanks!