I’m going to go out on a limb here (a nice sturdy one) and repeat what I might not have said quite so explicitly before: the Leica 21mm f/3.4 Super-Elmar-M ASPH might be the best wide angle lens ever produced at Leica, and might also be the best 21mm available today. The 24mm f/3.8 Elmar-M is in the same league also.
I have more material coming on the Leica 21mm f/3.4 SEM, but here’s a take from Frank Grasso, who is shooting it with film.
I was lucky enough to get a hold of this lens 2 weeks ago at B&H Photo. After reading your review in your Leica Guide, I was sold. I'm not a lens tech guru to say the least, but this lens is absolutely spectacular. Very sharp wide open and amazing flare control; you were right on the money with this lens. Without a doubt a keeper! Thanks for your trusted and well written reviews.
I included a few sample pics from scanned film using my .85 MP. I don't have the Zeiss 21mm viewfinder yet, but will order it from B&H through your site.
DIGLLOYD: almost makes me want to shoot film again! The 21/3.4 has resolving power way beyond what the Leica M9 sensor can record.