I've bought fully CLA'd Leicas from Youxin and been nothing but satisfied. I requested an ugly but working user M2 and he dug one up, fixed it up, did a full CLA and sold it to me for a very reasonable price. I was so pleased I checked back in not long after and nailed down a similar IIIF RD too, and a fully cleaned up 35/3.5 uncoated Elmar that's become one of my favorite lenses. All have worked perfectly for a few years now. He's prompt, wonderful with his communication and does great work.