Re: M&P Shield night sights
TFO's all the way. Not only are they a great night sight, but the fiber optic glows like a beacon in the day time, making your front sight easy to pick up. Think of it as a poor man's RMR, when distances are such that your front sight is all you need to see, which is the most likely case in CCW.
The thing I do not like about the big dot sights is they do not allow for enough precision when precision is what I want or need.