I have a bunch of their gear and I've found it to be well made. There was some intense discussion about the quality of their gear. One of the main stick points, was that the rails are NOT mil-spec. IIRC there are two areas that this is so. One that I remember right off hand has to do with the height of the rail column (I don't even know if that is a correct term or not), but essentially the column that holds the portion that you attach accessories to is not as tall (mil-spec). As a result, some accessories do not always work on their HG. I don't remember the other issue regarding mil-spec, but I think there is one more. With that said. Most everyone that has handled or uses their parts acknowledge that it is well made i.e., good coating, good sharp corners, precision milled, stout as hell etc... If you are wanting to set up a gun like an "operator" then you should go with somebody else (since the rails aren't mil-spec). But if you are wanting parts that function as promised, then I would certainly look their direction. I've handled several of their FF tubes and I thought they looked real good. Especially the LW FF tube they offer! And yes the snap on panels work on the rails.
HTH, and for some YMMV