The MiG-23/27 line has never been that popular amongst enthusists as they are, let's face it, not the sexyist beasts out there. They are however quite capable airframes, and let us not forget that most russian fighters are designed for the close in knife fight. So, with those big swing wings fully out I could see a MiG-23 giving an F-16 a run for its money in a turning fight.
Also in regards to the 30mm cannon, yes a single burst from it is more then enough to disable or destroy an F-16, american planes for the most part are not designed to take that kind of punishment. Warsaw pact aircraft on the other hand are, and can take a lot of punishment, not surprising when they are primarily built for a defensive role.