Obviously it involves variables - OP's budget, etc. I don't know what you do and in what types of environments you work work in, but machines which are capable of working continuously in high temperatures high-CPU-usage scenarios have definitely proven more useful for us in CAD/CAM duties. But we aren't talking desktop workstations here.
One of the reasons why I mentioned buying a proper mobile workstation - apart from the fact that these are also engineered for harsher usage, is that you can get fairly densely packed pixels on some, with machines like the Dell Precision M4300 offering even 1900 x 1200 on a 15" screen which can aid viewing (as long as your eyesight is up to it - I can't actually recommend WUXGA on 15")
I also mentioned they can be quite affordable. Compare the two - before further discounts, ~$1800 gets you a 2Ghz / 2Gb Santa Rosa Dell Precision M4300 with a tough, well-cooled all-magnesium bathtub shell (a shell, not an uber-bendy skin as on the Macbook Pro), including a Quadro FX360M, 1600 x 1020 WSXGA+ screen on a 15" display, 160Gb 7200RPM HDD and a 3-year, next-business-day onsite warranty.
With Apple, the same money gets you a 2Ghz Santa Rosa Macbook with a variable-quality polycarbonate shell that concedes somewhat more to style than cooling / functional efficiency, GMA graphics, 1200 x 800 screen, 160Gb 5400RPM HDD and a 3-year, mail/carry-in warranty which has usually a minimum turnaround of a week. In my Macbook experience last year it always took two weeks at least, and it's been within a week only a couple of times on the MBP.
Granted, the Macbook is around 600g lighter but even if you leave out the fact that the Precision is engineered far better to take a beating (both physically and in terms of load) than the Macbook, which would you honestly choose for Solidworks and related duties on the move?