Okay, I can give you a review of mine. The R-15 is nothing but a Bushmaster AR-15 configured to Remington's specs for hunting. It has things you can't find on a Bushmaster out-of-the-box, like a military-profile (NOT HBAR) 18" fluted barrel that's black-coated, a simple low-profile gas block, dipped camo finish, five-round magazine, and a vented free-float tube. The trigger is a 2-stage match, and breaks very cleanly at about 4-4.5 lbs. There are two sling swivels on the free-float tube, and a sling swivel where one would normally expect the fixed strap-loop to be at the base of the stock, so it's configured for a regular hunting sling as well as a bipod mount.
The barrel is a 1:9 twist, so it stabilizes everything from 40-grain Varmint Grenades up to 68-grain match hollowpoints (probably more, just talking about what I've run through it). I now have some Corbon 65-grain DPX's that I want to run through it to see how they do, I'd like to try a few things with that bullet like deer and other critters. The flattop receiver is standard, and needs riser blocks or, as I have mine configured, a Rock River forward-mount for the Nikon Omega scope (duplex reticle, 5" eye clearance). With the forward mount, you don't need an aftermarket charging handle or latch; otherwise, you'll want to add one so you have clearance from under the scope to chamber a round.
So how does it shoot? After adding a Gapper (small rubber plug that takes the play out from between the upper and lower -- $5, installs without tools in a few seconds), groups are right at 1/2-inch for five rounds of 55-grain FMJ or soft-point. Biggest group I've gotten so far was with a 50-grain VMAX, of all things, and it was 1.1" at 100 yards. It doesn't seem to produce flyers. I bought this rifle for coyote hunting, and it does just great for that. I have a Harris swivel bipod on the front, and a neoprene UltraFlex sling, plus I put a Bushmaster trigger guard on it to enlarge the trigger area for wearing gloves. In my opinion, this rifle is the ultimate coyote-hunting rig. It's light and well-balanced, versatile, and the 18" barrel is ideal for coyotes where I hunt. my longest shot would end up being about 350 yards, across a field, and this gun is plenty accurate for that. The only other thing I've added is stretch-cloth winter camo tape for snowy days.
That's my take on it, and based strictly on my needs and experience. As with any opinion, your mileage may vary. Hope this helps -- good luck!
Specialized