The enterprise drive is built for more reliability. IIRC it has 2 spindles as opposed to the 1 of the consumer lines. This means that the platter is more stable and so wears slower, decreasing the odds of failure. I'm surprised that it would be near the same price as the Blue line...is it on sale or a refurbished drive?
There should be no difference in performance that I'm aware of, when comparing drives of the same speeds. (i.e. 7200rpm to 7200rpm.)