Thanks for the comparative info @Freelancer and @Dianoda! It puts it into some perspective. My other surprise was the linearity of the falloff... I would have expected light decay to be more like it looks at f/5.6... as it is, it really drops fast!
@Freelancer... that MTF chart I believe is incorrectly color coded (or the legend was incorrectly labeled) so, assuming red is the usual f/8 and green is f/1.4... I'm not that impressed that there isn't a single point of the line at f/1.4 above, but that is true for Canon 35L as well. My main problem is, again, the fast drop out of the nice zone. By 1/3 of the frame you are below 0.7 and at f8 things are not much better
Perhaps I'm being overly demanding? Of course, I prefer samples rather than charts, so I'll wait for those