I've run a lot of different builds, but certainly not all of them. Since you asked for critique - here's mine:
As someone who recently upgraded from a 10.5" to an 11.5" - I have to admit, I kind of hate it. All the cool kids are saying 11.5 and 12.5 is the hotness now, because 10.5s are just too weak and loud. Here's my own take - I don't agree with any of that shit At ALL. There is a noticeable and significant handling difference going from a 10.5 up to 11.5, and I can only imagine moreso going to 12.5. 10.5 is the minimum BBL to keep 5.56 hitting hard - I do agree. But 10.5" is long enough that for CQB - it hits very hard. I run mine out to 200 yards all the time, and it hits that steel pretty darned hard - and quick. My take is if you want the most compact 5.56 that still hits stuff hard and is good for CQB and other shorter distances - 10.5 does the job just fine, and is hand Handy HANDY! Discard the suppressor and invest in ear-pro, run that sucker as a crazy-handy 10.5.
If you want more ballistics, then step up to a 16" and KISS and run a light weight barrel profile. I suppose you could 14.5 pin and weld, if you want to taper the length some. But IMHO, 12.5 is a lot of screwing around, and IMHO I think is way oversold. Personally, I say the 11.5/12.5 it's the .40 caliber of barrel lengths: promised to be the best parts of 9mm and .45 combined into one. When in actuality, it's the worst parts of those 2, combined into one; giving an overall dissatisfying clunky experience where it no longer is as light and handy, but it still didn't really hit any materially harder. But then, I don't screw with suppressors, and so if that's the plan, that's already a 16"+ sized package, so % delta of just 1 more inch maybe isn't as much or as noticable of a handling change, now that you have this huge 6"+ bulb of metal on the end anyway.
That's my take and going to be Fight'n Words for most folks - but my take is just go 10.5. Or go 14.5 P&W (or really, 16" Gunner profile).
Also, remove and discard that grossly overlength muzzle device. Why everyone wants 3" long muzzle devices after all the handwringing on barrel length just blows my mind. The A2 is the maximum acceptable muzzle device dimension, not the minimum.
On a final note, I'm not into long handguards. More mass. I don't hold a gun past middy-length, so I stop my handguards there, and in most 14.5 and 16" builds that means an exposed middy gas-block - which is just how I like it. Easy to get to for maintenance, and keeps the whole gun light and sleek.
Only exception to my own 12" disdane - make it in 6.5 Grendel and you have the ultimate most compact power machine there is. That little 12" guy in Grendel is a 600 yard capable gun with 1000 ft-lb impact energy out to 100 yards plus, in a package that's crazy-tiny. Grendel burn and pressure profile and bullet weight make it sing really nice in a 12" - that's an optimized length for a compact Grendel and there's a reason that was the standard offering when one could get a Brace-kit. In my secret volcano island lair - my Henchmen and Bikini-Clad guard babes are all getting issued 12" Grendel's.
(obviously my preferences - but hey, you asked! If this is a bit much - happy to delete)