I'd say go for it. I bought a RRA CAR A4 back in June, and I've been thrilled with it. Here are a few reasons, take 'em or leave 'em.
1. Fit and finish on the RRA is superior to a bunch of other ARs I looked at.
2. Haven't had any failures of any kind thus far. (Admittedly, I've only fired about 200 rounds max thus far, so take it for what it's worth)
3. Hogue grip. Standard. Woo woo.
4. Star safety lever. Much easier to manipulate with your thumb than standard.
5. RRA two-stage trigger. Supposedly helps with bump-firing (not tried it yet), but also aids in a nice smooth break when you squeeze.
6. Removable carry handle with rails. So you can mount a scope on the handle rails, or take it off and mount to the top rail directly. Up to you.
I happen to LIKE the heavy barrel sans attachments, despite the fact that it doesn't look exactly like an M4. This is for several reasons:
1. Supposedly slightly more accurate than a barrel with a comp.
2. No big flash halo from a "hider" around your barrel to dazzle you in dim lighting.
3. No stupendous racket caused by a comp (at least the kind that direct the blast to the side)
4. The slightly heavier barrel stands up to heat better if you like doing mag dumps, and helps inhibit muzzle rise. I've found that the rifle is well balanced with a full 30 rounder loaded up.
I'd recommend getting one with chrome-lined bore if you can. Mine's not, and so far my nads haven't fallen off like some here suggest, but it will make your cleaning easier if you have one, at the expense of some accuracy. I've heard that the barrel isn't 4150 steel like Bushmaster (it's 4140), but I'm not real concerned. The DEA has a contract with RRA for new ARs for their people, and I hear it's been going well. I work for the feds myself, and they USUALLY go with good stuff in the firearms dept. Heck, DHS went with Sig and HK for their new sidearm providers. Both are like one pistol for the price of two.
You can find mags on www.cdnninvestments.com. They have lots of 'em at reasonable prices.
My two cents, keep the change.