I'm very satisfied. Compared to cheap tap drill bits from local store (still more expensive than this set from Banggod) these bits are excellent. I tried one of them on a piece of iron (see attached pictures) where bits from local store weren't of any help and the result is perfect. I'm just a DYI hobist, not professional, so I can rate only based on my limited experience, but I think at least for occasional use these bits will be more than suitable.
Just to be clear I used the bit in electric drill to drill a hole only, then removed the bit, put into handle and did the taping slowly by hand. It went without applying force, the bit was sharp and even I proceeded carefully turning the bit backward few times, it wasn't necessary and it would work also in one go.

Fast shipping and normal delivery time. Product arrived well packaged and as described in selling page.
The set looks like good quality but i haven't test it. I do like the containing box ...
Look forward to use it in my projects.

A good product at a good price with Banggood good service. Satisfied !