I did quite a bit of research before choosing a new AR-15 last year. The Smith & Wesson M&P15T turned out to be the closest thing to ideal that I could find and the price was definitely right - $1150 after shipping and FFL fee. The 4140 steel barrel with 1:9 twist is more than sufficient for my use. 90% or more of the ammo that this rifle will be fed will be 55gr. .223 and I rarely empty even a single magazine in rapid succession.
The trigger on my M&P15 is a fantastic example of how good a standard GI trigger can be. I haven't measured pull weight but it feels like 6-7 lbs. There's no creep and the break is crisp and consistent. It's very smooth as well - no grittiness.
I've made a few changes to my M&P15T's configuration and there's a few more to come. I'm very impressed with every Magpul product I've purchased to date! I recently added the enhanced butt pad to the CTR stock (mostly to add a little length with stock fully extended), a MIAD grip with AA battery core (certainly the most comfortable grip I tried to date), and a B.A.D. lever.
The B.A.D. together with the BCM/VLTOR Gunfighter charging handle make a big difference in operating the weapon as just about everything, including clearing a double feed, may be done without removing your hand from fire control.
I'm still trying to figure out what I prefer out on the rail for a grip. I have a Knights Armament VFG that I find more comfortable than most VFG's and it's very lightweight. The ergonomics of a VFG are less than entirely comfortable though, specifically for the wrist. I had the opportunity to handle an AR with a Magpul AFG mounted. The position on the lower rail wasn't ideal for me but the ergonomics are a definite improvement over a standard VFG so I ordered one. If the AFG doesn't work out I'll likely go back to the vertical grip in a forward enough position to limit the wrist angle. I'm currently using the rail forend w/ ladder covers as a standard stock and I'm thinking this might also be preferable to a VFG.
I have a couple of VLTOR Scout light mounts, one offset, one standard low profile. Current light placement (pictured below) works well using the quad rail forend as a standard stock. Same arrangement on the other side of the rail works well for use with a VFG. This will likely have to change for use with the AFG - likely best without the offset. The light is a Streamlight PolyTac LED - extremely light, rugged, and 130 lumens for 3 hours continuous
The sling is something I've been fumbling with for a while trying to figure out what works well for me. I have a Blackhawk V-TAC quick adjust sling, a low profile Troy QD swivel mounton the left side rail closest to the receiver, and a Tango Down PR-4 QD swivel mount just behind the castle nut on the buffer tube. With this setup I can use it as either a 2-point configuration between the rail and the PR-4 or move both swivels to either side of the PR-4 and use it as a (quasi) single-point sling. Both work very well!
After experimenting with short range optics / RDS' I've found that the Eotech HWS seem to work best with my eyes. I much prefer the sight picture and find the reticle preferable to a single dot. I also like the absolute co-witness more than a lower 1/3rd. I ordered an Eotech 512 today and I'm definitely looking forward to my next trip to the range.
The current configuration is fairly light and very simple. The addition of an AFG and Eotech is about as far as I want to go with this rifle. I have a Harris 6-9" bipod and a 4.5-14X scope on quick mounts for long range shooting. The scope/mount has maintained zero with removal and remounting nearly a dozen times so far. Most of my shooting is at a distance of 100 yards or less and with iron sights or a RDS though.
Aside from what is visible the only other mod worth noting is the addition of a Spikes ST-T2 buffer. Cycling is smoother and recoil impulse is slightly reduced. Definitely worth the $30 I paid for it.
I'm going to be building / assembling (haven't decided completely yet) a second AR later this year using BCM as a supplier. I'm trying to decide what the focus of that weapon will be before I start ordering.