Things I liked: The Delrin seal did indeed seal it up tight with no teflon tape needed.
Things I would have changed: Nothing really. I mean, it's just a little steel adapter.
Things I liked: Although the description says otherwise, the thumbhole stock fit my brand new Condor rifle. Quality-made aluminum piece.
Things I would have changed: My main complaint with the thumbhole stock is that it makes taking the tank off more difficult. The stock must be completely removed using the thumbscrew in the pistol grip to refill the tank. Include instructions. Not that it is terribly difficult to figure out how to put on but there are some hints that would have been handy.
What others should know: The thumbhole stock is mostly a cosmetic add, but it does help stabilize & secure the tank in place as well. My rifled weighted 6 oz. more with the stock attached.