I have pretty much tried them all with poor results (yes, even the vaunted Youxin Ye, Oleg, FEDKA, etc), and finally developed a simple 2 step avoidance strategy that works, and works every time. It has also saved me a ton of money, and more importantly, a lot of aggravation.
First, never buy a camera that I cannot fix myself. That pretty much limits me to old folders and assorted mostly mechanical cameras, but that's OK. I learned a lot, and w/ the right tools it is fun to repair these things. Having a background as a mechanic, machinist and tool and die maker helps, but honestly, those skills have never been needed. Most of the repair work is common sense stuff for anyone w/ any mechanical ability.
Second, if I can't fix it, it gets sold w/ an accurate description on eBay and I buy another camera w/ a good description (preferably film tested) from a good seller. That way the most I'm out is two way shipping if there's a problem, and I limit my purchases to the US where I live to keep shipping costs low.
A lot of people have this delusion that if you get an old camera CLA'd it will last "another 20 years, 30 years, whatever). No, it won't. It's still an old camera. Metal fatigues, lubricants wear off and migrate, mold develops, rubber deteriorates, etc. Or, you just plain drop the thing. Anyone that has ever had an old car quickly learns that pouring money into it is a never ending situation. You fix one thing, another thing breaks. Just replace it.
