It appears the quality control for the TRR8 varies greatly. I bought one of the early ones several years ago, and I was very disappointed. You could actually watch the hammer move rearward, when pulling it through a very long SA let-off. DA was abnormally heavy, and gritty, out of the box. I was able to clean it up, to what it should have been, to begin with. It was common for many to have the barrel nut work lose, after it heated up a bit.

Some swear by it, others swear at it.