I will only have the 42`s personally,the advantages are obvious to those that use them.
Have had the Zeiss B/GAT& P's 7/42 round my neck the past 30+years, but no advantage against daylight and Scottish summer light (2 hours of dull in mid June) Swaro 7/30: 650gr, my Leica 8/42's are 940+.....
That looks superb FF.....really impressive leather work.