I've had one for a couple of years. Good gun for the price, runs really well. Over time I've bought a couple of other uppers and used the dpms lower with them until I bought a matching lower and it's done everything I've asked of it.
Only comments I'd make would be:
1) I believe it still comes with a plastic handguard - if you plan on replacing, it adds to the price ultimately and you may be able to find something that already has a railed guard - if that's what you want.
2) the flat top is great, but I found scope mounting a challenge with the handguard. Ended up going to med or hi (can't remember) rings to mount a 2-7 scope. Have since ditched that for a red dot,
3) I believe it will be a 16" barrel - for 3 gun that could be a little long, or it might be perfect for you - just thinkin out loud.
4) It has pretty decent quality, nice finish, no sharp edges or bad machining marks. Everything functions well,
Overall, it's a well made, decent quality, all metal good piece of kit. If it fits for what you want to do - then go for it.
One other thing to think about - if you plan to replace a bunch of parts it may be better / cheaper to find something that suits what you want. I'm not a mod nut, but I have replaced the hand guard, stock and end plate on mine which adds to the overall cost. It's a really good first AR, but not something I would recommend as a "platform" for major upgrades. If you wanna do that, think about the stripped route and build you gun of choice. If you think it works great for you pretty much as is, then it'll work great for you.