OK, here's the question for those of you who may be doing something similar: I do a lot of Stats (R mostly). I have the quad core linux desktop to run calculations overnight. However most of my actual work is done at Univ away from home. I have loved the unibody 13" (4meg)(before it graduated to pro) for the portability. Getting a new something or other anyway-debating if I should jump to the next or live with bogging down. The benchmarks however are highly centered around doing work with graphics/gaming/video etc. The calculations I have it doing involve a blinking cursor and listening to the fans roar. Will there be a noticeable difference with pure number crunching to justify the loss in portability and extra money or is it something along the line of waiting 16min for the MCMC chains rather than 17? Thanks.