Anybody have an M&P CORE?

[mcantar18c]

I don't own nor have ever shot a CORE. I do, however, have a fetish for Glocks with RMR's. Hope you don't mind me giving some input.
1. RMR's are absolutely awesome on pistols, and are entirely concealable and are really no more uncomfortable to carry than the same gun without the red dot. It's all about getting a good holster, and there are a number of them out there made for it. Dale Fricke makes an excellent holster (for red dot and non red dot pistols), if you do end up getting it.
2. As SouthPark said, the suppressor sights are necessary to co-witness with the red dot. Obvious reason this is good... if your batteries die or the sight otherwise fails, you can still use your sights. Less obvious reason... having the irons on the same plane as the dot makes the transition to automatically picking up the dot instead of looking for 2 points of reference significantly easier for your brain when you're getting started with red dot pistols.

I highly recommend both the red dot (specifically the RMR) and suppressor sights.