Unless you want the option to put optics on it do the regular 5" Pro. Me personally I can't stand the tall painted dot sights on the CORE even if they are raised for co-witnessing with an optic. At least with regular Pro you get normal height sights with fiber front and blacked out rear. If you do CORE and don't use an optic I would guess you would end up spending another $100+ to put new sights on it anyway.
With my bad eyes it is a requirement that I have a red dot sight. So, for me, it is worth every penny. I love the red dot sights, my second pistol with them.
I've got the Pro CORE, when I originally got it, my reasoning was that if I ever wanted optics, I wouldn't have to have the slide milled or buy another pistol. Since that time I've been shooting mostly IDPA matches (which don't allow optics) and I've been happy with it. I actually prefer the tall sights over the standard height on my full size M&P. Guess it depends on the individual. When my eyesight fails maybe I'll mount a big honking scope on top and a spotlight underneath it. (and a tripod mount to mount it)
I would put it slightly differently. If there is ANY reasonable likelihood you will ever want to put a optic on it, I would get the C.O.R.E. just to keep my options open. Like Bkruetz, I kind of like the tall sights, but I would likely replace the factory sights on either gun, so am not out anything there.