This morning I skipped my walk in order to do some pre-sunrise shooting with this lens. Of course, I was excited. Looking at the difference in size between my f/2 and this f/1.1, one could not help but be impressed, at least on the size. But, does size really matter? It’s how you use the lens, right? 
I had to have a false start, first, of course, or it just wouldn’t be me. I got the camera out of the bag, went to take a photo, depressed the meter and noticed that the arrow started flashing. Hmmm. I’ve never seen that and didn’t know what it meant. At first, I thought that the battery was dying. I was disappointed, started to head back to the car, get my S90, take some readings with it, then shoot. Then, in a moment of inspiration, I looked at the front of the lens … you got it, the cap was still on! Doh!!! So, that’s what that means. It means, too dark Dummy! Good that Leica actually meters through the lens or else I would have been shootin’ blanks! Score one for TTL!
OK. The meter is working just fine without the cap. Away I went. It was about 30 minutes before sunrise. I took to shooting through glass into the interiors of various shops, along the street, in the courtyards and little nooks and crannies where the sun wouldn’t be peeking through anytime soon. I wanted to see the light gathering ability.
Also, as this is a rather large lens, it protrudes into the viewfinder area on the right. At first I thought that this wouldn’t be an issue, as my other lens does the same … but not this much. After a very short time it became a major annoyance as I couldn’t see the lower right side of my frame and it’s really difficult to frame up a scene when almost 1/4 of it is missing. With a special assist by the Canon S90, I can show you what it looks like. Please note that the field of view for this lens is only inside of the outer frame lines, so as you can see, there is quite an obstruction. I was amazed at how much of the frame I actually pay attention to. I suppose that it is true: You don’t miss it until it’s gone! Score one for SLR!
I noticed, too, that the camera was much heavier, noticeably heavier and a lot less stealthy. This makes a big difference, I think in the way that I use it. Usually I’ll keep in it my hand, at my side, but with the bigger lens, I wore it around my neck. Part of this had to do with the fact that it isn’t my lens and I don’t want to tempt fate.
Regarding the light gathering ability: The stops are 1.1, 1.4, 2.0. This might lead one to believe that there two stops of additional light available, 1.4 and 1.1. However, there is only one, 1.4. f/1.1 is only 2/3 of a stop brighter than 1.4, and about 1 stop more than f/2, about 1 1/3.
Standard full-stop f-number scale
Including aperture value AV:
f/# 0.5 0.7 1.0 1.4 2 2.832 45 64 90 128 …
My meter verified this. While shooting, I switched between f/1.1 and f/2 and found only a one stop difference. Of course, that’s twice the light, but how often do you need it and what price do you pay to get that extra stop?
More later; I think, after I develop some film and see what the shots look like. Even after one morning of shooting with it, I doubt that it would be something that I would add to my arsenal unless I did lots of low light shooting and the one stop was critical. The lens needed depends on the type of shooting. Most of my Leica shooting is daylight, in the street, f/11. Why carry around a big tank of a lens for that? Who knows, I might change my mind in the next 10 days as I get to use it more and more. 
I’m sure that I’ll find more ways to use it, at least while I have it, then I will probably revert to my regular script … but you never can tell.
