I too have been wondering about this ammo. It is brass cased and made by a company known to produce good quality ammunition. It looks nice. But as to how hot it is, I have no idea.
If I were guessing. the velocities are probably closer to commercial specs, otherwise it would likely be marked as 5.56mm rather than 223. But you never know for sure without putting it through a chrono. I haven't.
That said, I'd say it's at least as good as most of the other commercial loads out there and some places have "decent" deals on this ammo compared to other similar types. It isn't exactly "cheap". But in regards to other brass cased 223 ammo, the price is about as good as anything out there right now.
I guess we'll have to wait until enough of this is bought to get a good opinion as to it's quality. But I admit I am glad to see yet another source for 223 ammo. With ammo availability as uncertain as it is today, every extra source is very beneficial.