just got two of their 'enhanced' ar-15 sets to build out. similar to the mega mkm series (i have a set in large frame for a future 6 or 6.5cm build, and i built out a small frame set into a valk). upper is machined with a flange to accept the handguards vs just attaching them to the barrel nut. seems way stronger and way less chance of affecting the barrel. only downside is you need to use their handguards but they seem to have a good selection so that's not holding you back. pricing is in the same ballpark so no downside there either.
seems that zev who bought mega has pretty much done away with these, seemed to be the biggest/best thing about mega so not sure why.