" While I want to improve my mixing setup I am NOT planning to do ANY room treatments or special mounting of the monitors. I currently mostly use headphones and reference recordings. I view adding monitors as a slight improvement over that setup. I know you are supposed to position monitors a certain way and add treatments to the walls and all of that...but I am NOT going to do any of that! smile"

Well, I understand the sentiment, but please consider trying as much of the above as possible. Otherwise just continue mixing on your headphones - you will get more accurate frequency balance if your headphones are relatively flat response. Save yourself the money of spending anything on monitors if you outright refuse to do any of the above.

Your statement "I currently mostly use headphones and reference recordings. I view adding monitors as a slight improvement over that setup." is only true if you take the effort to remove room modes on the low end of things, and comb filtering on the high end, then your view will very likely end up wrong and headphones are very possibly a better option.

-Scott