I took this class this past weekend:
https://www.modernsamuraiproject.com/reddotpistol Scott, the instructor, did a great job of actually being a teacher and helping all of us learn how to run a RDS. I had planned to write out a decent AAR of the class, but I'm not feeling up to it, so if you have any questions, ask away and I will answer them.
Summary: after 2 days of this class, I can run my RDS-equipped M&P as well as my iron-sighted M&Ps. Actually, the RDS is better/faster now that I can't focus on the front sight anymore thanks to being 50+. For example, my draw to the A-zone on an USPSA target from 7 yards was 1.35, which equals my best iron sights time, but I actually saw and used my red dot. I also did a 1.88 to the A zone from 25 yards, which I've never even come close to with irons. All from AIWB concealed.
Overall, I highly recommend the class. I now have the competence and confidence to use a RDS all of the time.