They are both great shooters. They wouldn't have lasted for decades if people weren't buying them. As far as shootability goes, I'd vote for which ever one has grips that fit your hand better. Some people prefer Colt and some people prefer S&W.

S&W's are generally easier to find and cheaper so they are probably the better value, but If you find a Colt in good condition at a good price there is no reason you shouldn't buy it if it's something you want. The price difference will vary from vendor to vendor and gun to gun but they generally should be pretty close - maybe $100 or $200 more for a Colt depending if we are talking about average shooter vs LNIB.