For your $1350 price range, one name... Daniel Defense.
$1800 ish then Colt Diemaco, Colt USA.
$2200+ Noveske, VLTOR, LMT, Knights Armament, Christiansen Arms.
Less than $1000. Just about everything else.
I would argue that the DD's and CC's are about there same price now that current model DD's are selling closer to the $2,000 mark or more.
Obviously not an apples to apples comparison what with DD offering numerous barrel/model choices and CC only offering two 'Old Skool' models (albeit extremely high quality 'Old Skool' designs) as complete rifles.
To the OP perhaps Stag is a brand worth looking into for a decent AR rifle in your price range that actually comes with a very good warranty while appearing to be well respected here at CGN (from what I've read here as I've never shot/owned a Stag).
I had the option last year of buying a new DD (purchased M4V7) or a CC, picked the DD based on a $600 savings over the CC SA20. However that DD pricing is long gone and now most DD's are closer to $2,000 after taxes (which is CC territory).
Also I wouldn't confuse a USA Colt as being the equal of Canadian Colt or even a Daniel Defense for that matter, due to the USA Colt's inferior barrels (Not Cold Hammer Forged like CC and DD), yet they are still a fine AR.
All this talk asking what is better direct impingement (DI) or piston is like asking which is transmission is better in a 4x4 manual or automatic; or which AR rifle is better is like asking which truck is better Ford, Chevy or Dodge. They all have their good and bad points whether it be availability, accuracy or reliability and of course price along with numerous other factors...
Tnsaf I'd suggest you figure out your intended use of your AR rifle: expected ammo. usage per month/year, plinking at the range, shooting distance(s), plans to compete and if so what discipline (CQB/3-Gun/SR...) and then ask for assistance based on a budget that is to include not only the rifle, but sites/optic(s), number of mag.'s and any other kit required.
Then after hearing some options research the heck out of everything AR for at least #6 months and then buy the best you can afford; or pick up an affordable starter AR like a Norinco or S+W MP15 (or other -$1,000 AR rifle since they hold their value well if cared for) now and learn what you want/need first hand.
Just my .02 cents. As I was in your position a few years back and the more I read and learned from the many more knowledgeable then I here at CGN the more my understanding grew and my mind changed on what was actually needed plus what was best in the AR market.
Cheers D