If you're going to shoot light loaded 10mm, then you should just get a .40 S&W. Same velocity/energy.
Full pressure 10mm is a lot of fun, and works very well. I carry Buffalo Bore, in the 220g hard cast for 4 legged threats and in the 180g JHP for more common defense scenarios.
I've got a few 10mm pistols, including the G20, a Dan Wesson Razorback, a S&W 1006, and a Springfield Range Officer Elite Operator (a 1911). I'm looking for a S&W 1076 to add to that collection.
This M&P is an interesting option, and I too wonder about durability. The S&W 1006 was legendary for its durability. It weighs about twice as much as the G20, all that steel comes at a cost, but it's a reliable, durable gun.