This is another one of those un-answerable questions, because the "correct" answer is a subjective opinion. My guess is there would be very little to gain, if you are sticking to MM cartridges, but my opinion is worthless to you; I haven't heard a Mc in years. If you are a perfectionist, if you will be worrying and wondering "what if", if you don't by the stand alone phono stage, then that's a consideration. If you have the dough, and if it's going to bug you, then by all means get the MP100. Also, why not compare the factory specs of the two phono sections? Talk to a rep at McIntosh, too.