I got my first 510 starter kit from him. Good price, fast shipping. Then I ordered some atomizers from him. Of 5, 2 didn't work at all. I emailed him about the situation, and he promptly replaced them, asking only that I send the bad ones back to him so he could check them out. I did so gladly.
A few months later, I ordered 10 more attys from him, and at least 2 (so far) of the lot are undersized. The empty mouthpiece that goes on the end is so tight that I can't get it off without pliers. Which means that no other cartridge will fit on it. I emailed him again, but got no reply.
So now I'm stuck with several attys I can't use. I used to refer people to him all the time on this forum, but no more. I can get attys anywhere, so I will. A shame really, as he had fair prices and 2-day shipping, which was nice. But if the product is unreliable, I'll have to go elsewhere.
I hope you have a better experience. Good luck!