Re: Colt Monolithic Upper- opinions?
$1400 is not all that good for a used 6940!! Complete rifles can be had NIB for <$1,600 and complete uppers can be had for <$1,000.
They are decent enough for a factory build. 16.1", free-floated, 1:7 Chrome lined MP tested barrels, standard with BUIS front and rear, and the monolithic rail is lighter than some competitors' versions. Accuracy is about what you'd expect (1.5MOA).
If you are looking to buy, for heaven's sake pass on the $1400 "deal" and look elsewhere.