For anyone who wonders too, I bought the lens today. It feels premium, mechanically it certainly complements precision of the M5 very well. Focusing is buttery, as is everything about the lens. I also bought an after market hood, which to me looks and functions a lot better than original LH6, it looks premium and is made same way (and it's half price of original hood). Also, speaking of this hood, it does NOT hinder use of filters (some on net tried to argue they cannot fit hood on lens with filter on, which is pure nonsense.
Hood obstructs corner in finder just a bit, but nothing that would interfere with framing. I have a second version coming tomorrow, same maker, but hood has small outside frame overall, so am not yet sure which I will keep. But this one feels premium and perfect match.
I'm yet to shoot a roll, but dry run indicates good handling, perfect balance on M5, and thumb focus as smooth as one would want to wish.