Hi Marc,
I am glad to hear it is so good. I had been looking for a lens in the 45mm range, but when I saw the size and aperture of the 45mm, I went with the 30-90mm instead. While I loved the utility of the lens and its center performance, mine did not seem to do very well in the corners and edges of the images. It went to Leica and they said they could not find anything wrong with it, so they want to see the body (which is fine with the other lenses). I am printing a book nearby in Karlsruhe in a few weeks, so I am just going to bring my body to the factory and go for a visit. Hopefully I will get a chance to try the 45mm then. If the performance is as good as you say, that's great news, but I have to admit I am still underwhelmed by the size and speed...given how good the 35mm is at 2.5, I was a bit disappointed that they could not make a smaller and faster 45mm. Still, the performance is more important than the size and weight to me in this system, and 2.8 is not exactly slow. If the 30-90 had performed as well as the 35mm or 70mm, that would have been more than enough for me, but unfortunately mine couldn't get tack sharp corners at any focal length or aperture, and that is a problem that is only going to get worse as the bodies increase in resolution. Assuming that is a design feature and not a fault with the camera or body, I will likely sell it and try to find a 45mm...
As for the 120mm, it performs so well for me that the occasional hunting does not bother me so much, but I can understand how someone might want a lens more similar to the 180mm if they were mostly working with quick moving subjects. I am not sure if I just got a great copy, but my 120mm is sharper at 2.5 than most lenses I have used in other systems...that along with the quality of the bokeh, lack of distortion and APO color and close focusing...well, I really don't have anything to criticize. I wind up shooting a lot more with it than I would an equivalent focal length on another system, just because of how well it draws. I have 24 images in my book and 8 of them with were with the 120mm, 10 with the 70mm, 2 with the 35mm, 1 with the 30-90 (at 83mm) and 1 with the M9 and 35mm summilux. Considering how long the 120mm is, I think the fact that 8 of 24 were shot with it is a testament to the quality of the lens...