The other thing with clones [of real optics] is there are clones and then there are cheaper clones of the clones.
I have a generic Guarder Aimpoint Comp M2 I got off Illusion like almost 10 years (whenever they first came out) and the thing is still going strong. It's built like a tank. It's been in the sun, in the rain, in the snow, in the sand... never a problem with it.
But it wasn't dirt cheap either.
Now I see some eBay copies, knobs flying off, dot stops working, difficulty adjusting etc. Those usually ARE dirt cheap, though. So you do get what you pay for, I think.
I got a cheap Micro T1 and got lucky, it works well. And have a few optics from Huang (EO 556, XPS, ACOG, another Aimpoint) and they're all pretty decent.
__________________
|