Overall my experience is that they will ultimately come through. But expect some bumps...
First time I ordered the whole package for an upper: sights, forearm, sling mounts, eotech, etc.
The order took way to long to get shipped, but eventually they shipped it.
All was well except the front sight which was defective.
They did replace the front sight.
The sight they sent back had a different defect.
They replaced that one and, to their credit, went an extra mile that resulted in an outstanding upper.
They do need to tighten up their shipping.
The holes in their QC are puzzling.
(It's soooo annoying when you see an obvious flaw and have to send something back!!!)
But man, they make a fine product when they pay attention.
and as I said: They stick with you till it's done. Least they did for me.