Got my M3 back from a CLA by Youxin about a month ago now, and have shot & developed about a dozen rolls through it.
When I sent it in, the slow speeds were sticking, the viewfinder was dirty, the frame preview was not working, and the rangefinder alignment was off. I also sent in a 50mm Dual Range Summicron that had haze and general dirt.
The M3's lugs were shot and the vulcanite was starting to go, so I had new lugs and covering added to the CLA.
Youxin's communication was great and his turnaround was fast. Everything is working now, exposures and focus are great, the viewfinder is amazing like an M3 should be. The Aki-Asahi recover was cleanly applied. The DR 'cron is clear as day and feels like the precision instrument it is.
In response to some of the issues other have noted with his work:
When I first got the camera back, I literally stuck my nose into it as far as I could and could detect a faint smell of machine oil. That smell has faded away and I've not seen any issues that suggest over-oiling.
Externally, there are still tiny areas like corners and deep grooves in both lens and body that have residual old dirt and grime. The film chamber, viewfinder, and all glass is clean as can be.
My overall conclusion is that, for those of us who want to shoot old film Leicas, and need have them brought up to proper working condition at a reasonable price and turnaround time, Youxin is a tremendous asset our community is very lucky to have. Is he the absolute last word in museum-quality restoration? Probably not. But he'll be seeing more business from me.
