OK, I have two M&P CORE 9mm Pro. One is factory sights the other is my "Open" competition gun with a Leupold Delta Point and a Carver Comp. When I got my first CORE I carried it as an EDC with the Leupold on it. It fits most of my holsters with or without the optic. I didn't find it any harder to conceal, however I did know quite a bit of the finish on the front edge of the sight but it has never bothered it. Once I got my Carver Comp I went almost all out with the open gun including an Apex trigger and all the springs etc. I use the iron sight CORE as an EDC when I am not carrying my Shield. I like them both.
If I wasn't using the optic on my open gun I would carry it, the comp just makes it a little long
Now for some details, I thought I wanted the RMR, I was very impressed with the demo a factory rep did where he took a Glock with an RMR and beat the sight on a table. Didn't seem to damage it, but I couldn't hit squat with it. Maybe it wasn't sighted in.
I went to my local GS and checked one out . The first thing I didn't like was the slight tint of the lense. Second, there is a slight magnification you will notice as you pan across targets. Kind of like holding your bifocals out in front of you and seeing things jump in size. I didn't care for that. SO I looked at the Leupold, clear lense, no maginification, larger window, and I love the triangular 7.5 MOA dot.
Fast forward, I have two of the Leupolds, one on my M&P R8 I use for steel challenge and similar matches. That revolver and sight have over 60,000 rounds down range, and I have only changed batteries twice that I recall. They say it will last up to two years and that it will begin to blink a few hours before going out. I've never seen it blink, but after about 8-9 months of heavy use it starts to get just a touch dimmer so I change it out.
The M&P CORE has not had as many rounds through it, maybe 20,000-30,000 but under much tougher conditions in 3-gun matches, getting tossed into grounding boxes and banging into barricades not to men getting blasted by the comp. I have no blast shield on it.
So, after all that my vote is YES, if you have a weapon that you can put an optic on, do it. Once you get used to it you will not believe the increase in speed getting shots on target.
In addition, another plug for the Leupold, I hate round dots. With my rx glasses I always see a blob or kind of a star. With the triangle it is crisp and in focus. Not sure why but I'll take it. The Leupold also comes with multiple mounts for different guns so you might not even need to have anything altered.