Alot of the higher end shooters use the fingertip, those that use more of their digit, or interior on the first digit tend to shoot guns with a very short and light pull (think 1911).
Cup in saucer is fine for single shots, but you don't have as much control as a high grip. Range warriors that just sit there and shoot do just fine with cup and saucer, but it's no different than shooting one handed. That's the beef. Your follow-ups are slow.