Despite the reassurances here by others and personal practice, I found the red dot too time consuming to acquire in the dark on my CORE. So I would not use it without adding equal height night sights to guide me to faster red dot acquisition for low (but not complete dark) light before turning light on. (Borrow one and take it into a dark room to try to find the red dot before buying or setting up yours that way.)

So while I love my CORE with a Trijicon RMR06 for range fun, and hunting, it is not currently my HD/bedside gun. I would reconsider if I broke down and put night sights on it too.

I've got a different M&P with night sights and laser grips that seems much faster to acquire target for me as a HD gun and am also considering that combo for b/u while hunting in bear country for things that might go bump in the night.

On the topic of on/off switches, have that feature on both the Trijicon and Burris FFIII. No problem. Just turn it on and leave it on any time you carry, put it bedside, whatever, or just leave it on constantly and replace the batteries once a year.