I have a Y strap as well as the similar strap from LeicaGoodies. The Y strap is wider and more comfortable, as well as adjustable in length. However, the Y strap's width necessitates a larger ring, which does not fit well in the lug of my R-D1. So I use the LeicaGoodies strap, though it's a couple inches shorter than I'd like.
I've had no issues with outright failure of the lug. However, the R-D1's lugs are made of brass, which is soft enough to be deformed at the edges by the ends of the split ring as it moves around. Leica lugs are made of steel, I think, and should be just fine.
I also tried this system with the LeicaGoodies hook, but that didn't work for me. The free-swiveling connector allows the camera to rotate into the wrong position on my hip, resulting in additional fumbling when reaching for the camera to shoot. That, IMO, defeats half the purpose of the strap.
Ari