I had the MX's.

here's the deal.

For street purposes, they are wonderful. Great in the rain I went through some 2" deep water on I75 with them at 70mph and the car didn't even wiggle a bit). Great in the dry.

For autox... The water keeps them from getting warmed up, so the compound isn't as sticky as the azenis. If it's really light rain/damp, the azenis will beat them hands down. Once the amount of water reaches the limits of the azenis water channeling the MX starts to take the lead. (basicly because you can't use sticky compound if you're hydroplaning).