I have a Mac Pro 4.1 with 2x2.26. Looking at x5690 or x5680 they are 3.46ghz vs 3.33ghz and the cost difference comes out to about about $150 vs $100 for a pair. I do mostly photoshop, lightroom, and corel painter. Is it worth getting the slightly faster x5690. It seems like the performance wouldn't even be noticeable between the two, unless I'm missing something? In the scheme of things $50 isn't that much though.