First of all, congrats on the purchase!
Secondly, DO NOT GET CAUGHT UP IN THE NAME BRAND GAME...
Sure, there are more expensive AR platforms out there that have better barrels and accessories than a bare bones inexpensive AR but keep in mind that AR's are modular and you can always upgrade pieces later should you feel the need to.
There will be some people out there that are name brand loyalists and they will tell you that your DPMS is not as good as "Their Daniel Defense" or "Their Colt" or "Their LWRC"—basically, they spent a large sum of money on their AR-15 so that automatically means that theirs is better than any AR that is under 1K. This is not always true. AR's are versatile so depending on what your intended use will be will be for the rifle, this will dictate how much or how little you will spend on an AR-15.
If you are shooting competition then you will eventually spend close to 2K and up for a lightweight AR platform that was built for accuracy. If you are looking for an AR for general plinking and varmint control then you will spend anywhere in the range of $600 on up.
Because AR-15's are modular and with literally hundreds of after market companies making parts and accessories...most owners will eventually put a lot of money into their AR's regardless of how much or how little they initially spent.
Not everybody that owns a 1K+ AR-15 is like this but there are those that feel the need to give their $.02 when they may or may not even have hard facts to back their views—take what you hear with a grain of salt.
Like it has already been stated, take it out and shoot it and base your own opinion on how the DPMS works for you.
I own an $800 Del-Ton and I just finished a 2K Daniel Defense/Spikes Tactical build and I equally like both of my AR's. I have never had any issues whatsoever with my Del-Ton and it has been very accurate and I wouldn't dream of parting with it. The only major differences between my two AR's other than cost is that the Del-Ton is light and my DD/Spikes is extremely heavy...
So again...congrats on your purchase and enjoy it!