Decided to finish a roll of 400 Arista in aR3M with the Super Elmar 21f3.4 (I think I will call it SE 21f3.4 in the future!). Not scientific or "lens testy". Just wanted to see how it behaves.
First impression, slightly higher contrast than the Biogon 21f4.5 - but not excessive. Edge fall is visible in bright sun (and stopped down to f11/f16) but modest. Sharpness is good, even very good. @ f3.4 and f4 - it is remarkably even across the image-area ( as born out by the MTF curves). It is a worthy successor to the SA 21f3.4!
Ergonomics are excellent. Easy to use the aperture ring. The nifty hood is nice as it "extends" the barrel a bit and gives you a better grip - it sits in the palm of your hand very comfortably.
Is it better than the old SA 21f3.4 or the ZM Biogon 21f4.5? Dont know in exact numbers (MTF/Lpmm/ etc - but it is certainly up there among the really, really good lenses for a M-mount.
None of the shots so far were done to check distorsion - need a tripod for that.
Is it worth close to $3000 - well, I dont know. I dont think it is twice or three times better than a ZM Biogon 21f4.5 - they are both superb lenses. It is all a matter of choice.
I took the plunge as ANY lens which is 21f3.4 is interesting to me ( I have used SA 21's since 1964) and it is almost 6 years since I last bought a new Leica lens.
If you check our Flickr and use the tag "Leica Super Elmar 21mm f3.4" - there should be 10-11 shots up now. More to come with the PanF+ - but probably not for a day or two (need to mix up some developer etc).