^^^This^^^ I bought a 6920 for $1k and it was a piece of crap, the machining was horrible and the upper wobbled on the lower. I had realistic expectations and it was noticeably lower than that. For $1700 you can get a PWS (very highly recommended). Good luck and DO NOT spend $1700 on a Colt.
The Mil-STD and TDP calls for the upper-to-lower fit be such that a soldier can easily push out the take down pin without tools. It's not an accident that Colt AR15's are that way. It doesn't mean it's a piece of crap, and there are hardly any rifles that have the parts pedigree that Colt's do.
I'm not a Colt fanboy, and I don't own any complete rifles from them. The only Colt stuff I have is from surplus parts kits from export M16A1's, and whatever I can find that was made between 1961 and 1970. Even those parts exceed the "standards" that I commonly see in the AR15 industry.
Colt parts alone are worth 150% to 200% of imitation parts on the market in most cases, whether talking about detents, springs, hammers, triggers, bolt carriers, bolts, pins, uppers, etc. Lowers usually command 300%-800% value compared to others, depending on when they were made.
To describe a Colt as a "piece of crap" is way off the mark in terms of the actual materials sourcing, manufacturing processes, and certifications/proofing that goes into a Colt rifle versus one of the other alphabet vismods. There are precious few companies that even come close to the parts and assembly methods that go into a Colt.
I used to buy into the hype that they were simply made by the lowest bidder, until I started taking other company's rifles into harsh conditions and running them in high volume, at which point things you would never expect to break or corrode, did. I never had any problems with Colt M16A1's, M16A2's, M4's, or M4A1's in the Army, and my experience with them spanned the extreme climates of Korea to Panama, all over the US, and the Middle East, in field conditions as a combat arms soldier who lived in the mud/ice/snow/dust, not in a tent in the rear with the gear.
The Colt-produced AR15 is one of the most well-engineered, bugs worked out, viable, successful assault rifle designs in the world. There really aren't any rifles that come near it in terms of the design, engineering, improvements, and continued advancement to make it as optimal of a rifle/carbine as possible. What you see on the shelves at your local gun store may look like AR15's, but they share really nothing in common with the Colt-produced guns, other than being black and having parts that were made to look and be as dimensionally similar as possible.
There are a few companies that have obtained the TDP and actually followed it, who are the exceptions. Just looking over it would really open your eyes as to what's really different between a Mil-spec gun and the rest. Name any part, and there is a laundry list you have never heard of in respect to materials, min/max dims, metallurgy, surface hardness, assembly methods, inspections, and proofing/QC. That includes everything from the Cadmium-plated detents, to the grade of wire for the springs. It specifies the softness of the carrier key, to the hardness of the upper receiver and Moly-resin that is sprayed and baked on inside the upper.
Talk to 98% of the AR15 "manufacturers" at SHOT Show, and they will look you in the eyes with complete ignorance about everything I mentioned above, to include many of the companies that have fad-like followings because of one or two unique features to their brand
For the money, I really can't see how Colt is offering their AR15's on the market for the prices they do. Go piece one together using only Colt parts on Brownell's and see what happens to your cart. The 6920 is one of the best deals on the market right now. It is light years ahead of anything else in that price range, other than piecing together a BCM or DD carbine.