In two years your machine won't be normal, it will be outdated and slow, by a long margin. the ix cpus are going to be old in just a couple of months because intel has a new architecture around the corner, then in a year or so they 'll shrink the die which will offer huge benefits, imagine where you ll be in two years. And that's not even mentioning what AMD will be doing with the APUS which are THE cores that will be useful for physics with their parallelism.
I won't go into the stronger built quality points you make, I don't think any of them is valid.
So essentially what some here have been saying is that in two years time both a c2d and and ix will be old technology, their difference from one another much smaller, much much smaller, than the difference from the overall tec growth. Hence the clever thing to do is not to go for a 10% gain now and in two years be trailing by 40-50%, but take a 10% quality hit today and in two years be on par with then current tech. It's a no brainer for me.