If the M&P comes with 'standard' Trijicons, note the front sight is bigger/brighter than the rear sites (lots of folks seem unaware of this). As such, my eye is naturally drawn to and focuses on the front sight, which is why Trijicon does it this way.
I resisted night sights for years because I was not willing to give up the clarity of 3 white dots in light for the night sights. Somewhere along the line, night sights changed - maybe it's because they now have white circles around the dots or ?, but to me night sights now look much better in light than the old ones.
BTW-I thought about going the green front/amber rear combo, but with the bigger/brighter front sight as found on the Trijicons, I find it impossible to mistake the front sight dot for a rear. I've also held the gun at enough of an angle in order to have one of the rear sights in the middle, and I see no way I'd every make that mistake as it feels so darn wrong/unnatural (focus aside) that I can't ever see having the gun cranked that far left/right in order to mistakenly place one of the rear sights in the center!
FWIW, my old retired bed gun was a S&W Sigma with factory Trijicons. The sights are now over 12 years old, and while not nearly as bright as when new, they still have plenty of usable years of life left for me.
Night sights are just another tool in the box for me - if I don't need 'em, they ain't hurtin' a thing by being there. If I do need 'em or could use 'em...well, there they are!
Hard to go wrong with the Trijicons from S&W as you avoid the expense, hassle, and sighting in required when replacing stock contrasting sights.
For years my old Sigma was my only gun with night sights, but over the last few years I've upgraded my P229R and two XDs with them (all Trijicon green).