I love Leica lenses and agree they are the main reason to buy a Leica rangefinder. I do use a Zeiss Sonnar 50 f/1.5 for its unique and gorgeous character, and a few CV lenses as well. But, my 50 Summilux ASPH is unbeatable in my opinion.
In the case of the 7A 50 f/1.1, I just know I’m not going to buy a Noctilux. If I do need to shoot faster than f/1.4 (rarej, the 7A does quite nicely. I was concerned when I needed to do the focus adjustment when I bought it. The instructions led me through it and now it’s dialed in perfectly on my M10 Monochrom. Center sharpness is excellent, in my opinion. I’m glad I bought the 7A lens.