It's also somewhat of a "stealth" lens - in a lot of places you are limited to a lens of no more than 6 inches, but you need the reach and the low light capability. For example, when shooting hockey from the stands, I'm almost always shooting at 200mm, so using the fixed 200 f2.8 is just as easy as the 70-200 f2.8 (much lighter over the course of a game, also) and far less likely to draw the attention of the arena staff who tend to frown on larger "professional" lenses (it also helps that the 200 is black, so it doesn't stand out like a lot of the other L lenses). I find that the image quality is excellent.