Basically mac will prolly give you more stability in terms of viruses and worrying about bad hardware conflicts as everything that goes into a mac is more tightly controlled. But you will pay more for apps and have a lot less flexibility then you het with a pc.

In the end it's personal choice because there are going to be people that would fight to the death arguing one is better then the other.

I do not think you are going to find a mac configuration that can compete with the dual 16 core xeon socket 2011 board that Dave has suggested though and a pocket calculator would be better then the system you have now.