I've used the u edges now for about a month, and a very busy month. I am very satisfied with them, and feel they are living up to the claims. I pushed alot of gravel, and over alot of lawns, and had no problems. In fact, now i have a narrow strip in the middle that keeps digging up grass, and its from the rubber "horses hoof" in the center of my Boss. It is the only thing that digs in. I am currently trying to figure out a way to replace that with urethane!
I mounted my edge too low initially, and ripped the urethane on one side. MTS stood behind their edge even though it was probably my fault, and shipped me a new one the next day, no questions asked! Customer service is awesome, and they do believe in and stand behind everything they say!
The edge will last a heck of a long time, I can tell that. It will more than make up for the additional cost over steel.
Overall I am very satisfied, and would highly recommend one of the MTS edges.