P1408 is on the money. I'll try to expound...
As far as the durability and reliabilty, his comment was something like "If you backed up a semmi truck full of .45 ammo, the HK would probalbly win the day." In the end it seems he thinks the M&P is just better suited as a service pistol. What I generally say to guys at work that ask about HK pistols is this...
I believe the HK line of pistols are the best enginerd, reliable and durable pistols on the market. As a pure machine in an assinged task, they can't be beat. However, sometimes I think the Germans totally disreagaurd the fact that it has to interface with a human hand.
There is no doubt it will be popular with some and it is very evident that Larry has done all that could be done to make it more ergonamic. I think it is obvious that even he thinks they still fell short on this. Reliability and durability don't much matter if the pistol is too large or too fat for most to use effectively.
That, of course is just my take. I must admit...I was not surprised by this at all. The M&P has meny more features that are "1911 like". Larry said it was a "product improved Glock". I read that as a good blending between a Glock ( As the man says, "it's a Glock world. All others are on the perifery") and the 1911.
I was done being surprised at Larry's opinions after the first phone conversation I ever had with him. It went some thing like "just get a Glock..." if I recall correctly...I followed his advice, but also got a couple "high end" 1911s as well.