I've had 3 each bought at least a year apart so can't have been from the same batch and all have been beyond temperamental. Of all the optics I've owned, which is a fair few now, they're by far the worst- the other G&p stuff is alright but they're all basically rebranded China clones anwayI know Sam_G had one that was fairly terrible as well as a few other friends and players. As I say, I've seen a few good but they're outnumbered greatly by the bad, but then you get what you pay for, even more so with these kind of things so cheap optics are always going to be 50/50 or worse anyway.
In my opinion and experience my original comment is justified.