Well I have one from bestpriceecig and one from Infinite. The infinite is nice and clearly 1 piece, had no clear coat and gets a nice tarnish on the
mod and button as well and was really clean inside and out. Button has a c-clamp. The
threading on the button and the 510 is very nice and tight. The button does grab if you press on the outside of it, but I think with a polish this could be fixed I am just too afraid to mess with the c-clamp to take this button apart without the proper tools.
The bestpriceecig clone had a clear coat and I think the button may have been coated as well cause it did not seem to tarnish. It also has black marks on the inside which I don't know what that is from, machining I guess. The 510 isn't as tight as the Infinite either. The button is easier to disassemble as the pin in the center screws in as opposed to being held in by a c-clamp. Also this button had magnets in it.
Both were pretty nice but I feel the infinite takes the edge just because of the tighter threading and lack of clear coat and clear 1 piece design. Otherwise they both feel about the same in my hand.