Coincidentally, I took my Shield down to David's yesterday for the same work that John had done. Also took my M&P 9L for some Bowie magic to make it a tactical tack driver.
I have had several M&P's done by David and they are all great. His workmanship is first rate, and he is a good guy. Like John, I met him at TDI.
He should have them done when I go down to TDI for my annual re-take of Close Quarters 3 & 4, in late March.
What John did not mention is that TDI is a great place to train. Mr. Benner and his staff are absolutely first rate.
S/F,
RAS