Difference Between Tractio "AA" and "A" Tires?

[Garibaldi]

I'm looking to replace the EMTs on my '00 FRC. Is there a HUGE difference in traction between a tire with an "A" Traction Rating and an "AA" Traction Rating? I've searched around and find folks describing both kinds of tires as being "fantastic in the wet (dry)!"

[Luke@tirerack]

the traction rating in the UTQG code is strictly wet traction and it equates to approx. 20 feet shorter stopping in the wet from 60 mph for the "AA" rated tire