I have 2 NEA barrels on my Ar's. Both are minute of angle on those builds. One in 223 wylde and one in 556,
Oh yeah, they are on NEA uppers and lowers that I bought used when I built both rifles and I have had Zero issues. Guns are abused rarely cleaned and usually go through around 400 plus rounds per day when they are taken to the range. They have been used in sandy muddy snow and slushy conditions at out door ranges.
People who don't like NEA's may have heard of or had issues with them, but the two I have are excellent and to date have been 100% reliable and I would personally rely on them in a SHTF situation. I carried a C7 for three years and would put the two NEA's I own up against the C7 I carried for accuracy and reliability every day of the week.