For what it's worth, the single Russian made LTM lens I used seemed okay. Not stellar, but at least average. It was a 50mm f/2.8 Industar. It was cheap enough that I could roll the dice without worrying about getting burned. If it sucked I could put it in the display case next to the half frame P&S and Instamatics. Sometimes you get a good one, and sometimes you don't. Forrest Gump's box of chocolates. Just know what you're getting into. (This was the talk I should have heard from a certain foreign car dealer ten years ago! *cough MINI)
If you want quality you can bank on and have the money to spend, by all means get the real McCoy. The build quality and results of my genuine Leica lens are really pleasing!