Tyre wear is better, car is generally easier to drive, and you get more ability to change line (good for passing slower traffic), but results vary for many.
I was using the TOP Micro Pro diffs up front for some time, then out of the blue I killed two in two meets, with the EX and new diff coming I could not be bothered buying the parts to rebuild them.
Only problem is I have been running the spool for 3 meets now, and loathing it in every way.