Like all porn POV depends on the quality of the girl and the interaction between her and the camera. If all she is doing is sucking to get a paycheck then some different camera angles may serve to reduce monotany. However, if the girls is totally into her work (ie: Seymore Butts on a good day before his TV show) then she has the power to make you feel like it really is your cock she's working. If you can feel like the only two people in the scene are you and the whore then you have found a strokeworthy POV.