Are they reliable?

I've had good luck with ASC...fyi

I have a couple of the older ones that have worked well over the years.  When I say older, they are probably pre 2010 manufacture, I bought sometime around the time I bought my R-25 which was before I signed up for this forum.  I don't remember the exact date to be honest.  Originally they functioned fine, but most only reported being only able to get 19 rounds in the mag.  I don't have any experience with their newer production mags.  A lot could have changed, but if they are built to the same specs they should be good to go.  I mostly use Pmags fwiw.