I have a M&P 15 sport II. Fold down rear sight and fixed front sight. I am looking at the Romeo 5 red dot sight. I understand it does not come with a lower 1/3 co-witness. I am looking at the American Defense AD-T1-10. It is advertised as an Absolute co-witness. Some people are saying with the Romeo 5 it will put it as a 1/3 because of the Romeo height. AD makes the AD-T1-11 that they advertise as a lower 1/3. A guy said in a comment section that one is too tall. I hope somebody on here can give me some info before I purchase. I prefer the 1/3