The mobility of the MBP would be nice, but I need to make sure my needs are met in the office before the luxury of mobility. I will be doing a lot of testing and reviewing of productivity applications on multiple platforms, so I'd like to run Linux and Windows within OSX most of the time. I would have two, eventually 3 monitors for the Mac Pro, but the MBP is limited to 1 external monitor. I would have 8GB ram in either. What I'm wondering is how big of a difference a 2.9ghz quad core makes vs. 2.8ghz dual core in the MBP? Other than the extra USB and FW ports, that's all I see an advantage in. The apps I'll be testing aren't by themselves labor intensive, but I may be doing a lot of web dev and graphics work in photoshop and whatnot in OSX while having the other OS's running - that will be the peak of my workload. So, thoughts on dual core vs. quad - worth losing mobility for 2 more cores?