nice find Mark.....not sure if I got the performance one when my pump went out 6yrs ago
I just read a review where the guy bought the performance pump and took the back plate off to verify it was the performace pump and it was the standard replacement, not the performance pump....he went through 3 before he gave up.
edit: nope didn't get the perfromance one when I replaced it. Looks like this would give me an excuse to flush the cooling system.