I had quite a bit of experience with the early MPs as they were our issue pistol. I had a 5" P/C model also. Many of us soon discovered the 4"? model shot better accuracy wise that the 5" models. Dont know about now. 5" is fine Im sure. I would buy the CORE model ( if you want the MRD )over the other just because I dont care for cut slides and ports. Its a light pistol to start and only 9mm . The CORE is 100 or more cheaper, if you dont want an MRD the base model is way cheaper. I have no idea how the trigger is in them or if the cheezy set screw overtravel is good or not. For 100 or a bit more you can buy an APEX trigger (brownells has them for 115 now) and great videos to help install, and have a great trigger 3.5 for competition or 4.0 for duty. If you go with the MRD you will need the taller sights. Otherwise I would buy the very good Dawson Precision Fiber optic adjustable sights. You can put a light on it so dont really need night sights. F/O glows a bit at night with the flashlight. Adjustable sights always make ammo changes easier. If you are going to shoot the same ammo all the time fixed are fine. Down the road if you want more accuracy some guys install an APEX barrel. Mine shot fine without any barrel change. Just my opinion.
