I have a Postons DP, which is almost the same, and the fit and finish is nowhere near that of a THDP. BUT ITS $250 CHEAPER. I upgraded because my stocker went to sh** on me. I does spool faster and I gained about 1mph. So unless you HAVE to get something else, I would keep the stocker. But if you need something and dont want to shell out $500, they are not too bad.
The hardest thing is keeping them from leaking near the elbow. My has a small leak, but I cant hear it so I dont worry about it too much