I thought these comments on the new Voigtlander 28/2 by Mainline Photo in Australia may be of interest.
"NEW 28mm f2 ULTRON Voigtlander M mount
So how does this new compact 28mm perform?
This lens has already been on test under wraps by Mr Rapidwinder/secret agent himself Tom Abrahamson and here some of his photos with the new Ultron.
Our first photos below show this lens to be another little gem. It has outperformed the 28mm 2.8 asph, 2.8 Elmarit and the old Ultron 1.9 (thats all the lenses we had close to hand!)
First impressions in our very subjective and non scientific showroom testing/playing are... that for less than $600 why would you buy any other 28mm M mount lens! Beautifully made it certainly seems to be the best built Voigtlander lens to date. Also it does not obscure more than a small part of the corner of the Viewfinder even with the lens hood on.
Cosina has taken out the aspherical element in the new Ultron 28mm M which has made this lens a more forgiving performer especially on the digital M8.
The lens is made in a similar mould to the current new Noktons with a focus tab the lens displays a nice medium contrast level.
Very nice and sharp (without what we would call becoming harsh) with no focus shift seen."