I had one. It worked fine. Geissele worked perfectly. Main gripes were the sharp edges (overly square features), enormous finger hole and monster logo.
Also not a fan of 6061T6 that is prone to crack easily, especially with all the sharp milled corners and thin features.
Some key radius tooling would certainly help to get by with this cheaper material.
I polished it out and replated in FDE then built it up with a modified Bolt Catch/Release for a friend. He says he loves it or maybe just overwhelmed by the new trigger.....
For the money, I think it did its job, but overall is not on par with standard FN quality.