Not an expert
Not really an AR person but here's my experience/opinion.
I've shot Armalite
I've shot Eagle
I've shot Bushmaster
I've owned/shot an older Colt Sporter II Green Label (traded it on a jeep, wish I still had it).
There was something different about the Colt. I can't quite put a finger on it, but it was better. Sub MOA with a chrome lined bore helped. The appearance, the way things fit, the way it shot, etc. etc.
You should be able to pick up one of those lightly used for under $1000. Given the choice between a new AR for about the same money, and the old Colt, I'd buy the old Colt. People make out like they're big money, but when I was selling mine, it ended up being about a $850-$900 dollar rifle.
Also, I wouldn't personally get a Whizbang Tacticool Uber Carbine. I'd get a 20" A2. The Colter Sporter II is about as close to an M16 as you can get.