Well, I have a series 70 and a series 80 Gold Cup. The 70 is blue, the 80 SS. Frankly, there is little difference between them R/E the trigger pulls. The 80 is a smidgen more accurate then the 70, the 70 has that beautiful Colt Royal Blue finish. Both have the standard spur hammer, and hammer bite has not been a problem even though I have big hands. Both guns feed almost anything I feed them, including cast 200 grain semi-waddcutters, with very good reliability. Both utilize the Colt Eliason adj. rear sight, and it is very sturdy. Series 70 guns seem to bring a premium in price, I guess because of the lack of a firing pin safety. I believe the older series 70 and 80 Colts, built on old machinery, were dependant on hand fitting for best tolerances and accuracy. This quality level did vary some. I do hear the newest Colt 1911's, made on modern, close tolerance machinery, have been showing more consistent fit and accuracy.
Now to throw a fly in the ointment - My Kimber Custom Target 1911 is more accurate then either Colt, better fit, and has NEVER malfunctioned, in many, many rounds of factory and reloads. They are under 1K, in the satin blue finish.
Larry