That DPMS will be fine. No doubt it will be the sportical (for that price) with no case deflector, dust cover or forward assist. But it will shoot when you pull the trigger and hit what you aim at.
True, I think the M&P sport would be better, but I don't think you will ever find one for 600 bucks again. Cabelas had them on sale for that price before last Christmas, but you can't find them in stock anywhere now. At the last gun show I saw two, one for 750 the other for 899 (mark down from 999, of all things...).
You want to check out the Sportical, get on DPMS website and view it. Need more info, go to the ar15 forum, click on industry, scroll down to DPMS and read away. The company posts a lot of info there.