This thread will also be of interest. Ampng its participants are pilots who flew the Mig 23 in the USA as part of Consant Peg and a russian pilot who trained on it with Iraqi pilots
MiG-23MS - Performance Characteristics?
The long and the short of it was that the BN version was an excellent GA aircraft but no good as a dog fighter but later versions were a lot better. All versions had excellent acceleration and were easy to maintain with quick turn around times.
May I remind everyone that in combat it lost out to the F15 and F16 which is only to be expected but when it entered service it was mainly up against F104, F100, Mirage III and F5A in Nato. Against these aircraft the Mig 23 was a very real threat.