Since I started this thread I've only put around 500 miles on them so I can't really give any kind of review. We do have roughly 2,000 additional miles planned this year though so I'll follow up in the fall.
The Maxxis is a great tire, I've had them myself. Honestly, from what I've read I doubt there's much difference between the two. The higher speed rating is a lot of extra piece of mind for me. That, and the availability over the Maxxis helped too. There was little difference in price so that didn't factor in my decision.
I looked at the new tires once unmounted compared to the old Towstars and the difference was HUGE in weight and overall feel. Granted the old tires were 8 ply and I went to a 10 but the Towstars were VERY soft.
Also people (myself included) have had issues when buying Maxxis with as much a year old date code at time of purchase. To some that's not and issue but you lost a year of your warranty. The Carlisle's I bought were three months old the day I bought them.