Saw on YouTube many hackers building their own 'Mac Pros' with i7 CPUs and ATI 5780 GPUs, etc etc and in the end they have a 'Fast' mac pro equivalent at a fraction of the price. Some spent less than Eur 500. Funny enough, some of them, even went out and got a PowerMac G5 and modded the case to get a Mac Pro 'authenticity'. What are your thoughts on this? (or experiences) Is it really worth the gamble?