Erm, the head that OP linked to doesn't actually have any Opteka branding, it's just sold by them. I've seen the same head sold by many people and companies with either of the two levers but everything else being the same. So, apart from the lever I have used the same head and am qualified to comment on its quality.
As for the issues I brought up, the sagging or hitching is only evident when I do macros but with everything else it is a non-issue and is also easy enough to deal with. I have heard of other ballheads costing 2 or 3 times as much having the same issue, sometimes to a worse extent (not making assumptions here but going off what I've heard from others that have actually used the products) so it is hardly a consequence of the price. Many people are still happy with this, so yes it would meet the average person's standards.
And the plates being loose, you don't seem to understand just how loose they were. There's literally 2 or 3 strips of tape in there and the tape measure about 0.1mm thick, so at most I've added a 0.3mm shim and that's probably too much. All that shim does is take up any variance between the two plates that I own (which came with the head), I'd say that's a pretty high tolerance. I've actually just measured the two plates with my calipers and there is indeed exactly 0.3mm difference between them.
So, if that isn't up to your standards and qualifies it as junk then you must be displeased with a lot of things in life.
I think I've been very rational too (definition: having or exercising reason, sound judgment, or good sense), in fact I seem to be the only person putting across reasons and proof instead of jsut making assumptions.