By and large, Colt enjoys a reputation for consistently functional pistols, but the fit, finish, and other aesthetics is very inconsistent. the spectrum ranges from gorgeous bargains for the price asked, to outright abortions with a large in-between population.
Some of the common issues I have seen in the past couple of years is mismatched parts thrown on from the bin (WWI stuff on S70s, Ambidextrous panels on a WWI, etc), misaligned recoil spring channel, trigger slop, faulty plunger tube staking, mis-ground/beveled surfaces, horrendously cut grip panels, excessive tool marking, and rusting stainless, NIB. Colt switching over from the old Bridgeport to CNC technology will give more consistency (particularly with the slides) but CNC won't stop ugly, miscut grips or the wrong series part from being slapped on.
The rule for a Colt is to be able to put your eyes and hands on it before buying, or expect a gamble.