I did, but that was the very first generation of Intel Mac Pro -- five years ago! -- and since then some Apple tax seems to have crept in, progressively so at the high end. Today's dual-socket Mac Pro seems to come with Xeon E5620, E5650, or E5670 at price differentials of £1200 and then £1000, compared with chip price differentials of £900 and then £600. At that rate you could in theory save twenty-five quid by buying the E5620 one, throwing its CPUs in the bin, and buying two E5670s on the open market.

I think there's been some catching-up recently in the non-Apple world in the arena of making PCs that are actually quiet. At least these days we have SSDs and don't have to put up with the scream of 10k or 15k RPM winchesters.

Peter