I've worn out every set of Continentals I've bought..never seen any cracking or checking...
Have a set of Extreme Contact DWS, with 30K on them, installed on the Volvo T5, they are still at 7/32" tread depth, no checking/cracking.
Just bought a set of Eco Contacts for the Corolla, only 10K on them so far, they look great. They're replacing a set of Contacts that went about 50K and looked great when they got down to the wear bars...