I really like the S&W tactical model. There is a lot of comments about the model, and how U can possibly make the same gun for less money. But, I've seen a few threads on that model on the Ar15 site, and the prices for the parts are discussed and added up. Actually, the S&W version is cheaper than trying to buy the same parts and doing it yourself - from what I have read. Also, U get the S&W awesome service.
Really haven't seen neg stuff about them. If I had the cash, I'd buy one. The tac model looks really sweet too.