I was browsing the 2k5 boards looking for some information on if/when the next roster update is going to come out (it always seems to be within a week after I start a new league) and came across this FAQ:
26. [NFL2K5] What does "Performance EQ" really do?
If you have performance EQ enabled all player attributes get adjusted so there is less difference between a good value and a bad value. What this amounts to is poor players performing better and all stars performing worse. All stars will still perform better than poor players but not by as much as with EQ disabled. So the Patriots will still be a better team than the Browns, but with EQ enabled the Browns at least have a chance of winning. :)
As I've mentioned before, the next league will be All Pro difficulty, EQ on. The latest concensus (among those who have an opinion) is that All Pro is a more fun difficulty setting than Legendary and so that's what we'll use. Similarly, we'll be using EQ because losing the the Patriots every week is less fun than having a shot.
Edit: Mostly I wanted to share the information I had found but since my comments might cause some to wonder when the next league will start, I'll throw some tentative dates out. The next league will not start until the end of the GWJFL 2005 regular season. In the meantime, I plan to cover the interim 4 or so weeks with a tournament. Watch this forum (specifically tomorrow or the next day) for additional information about that.