I am considering one of these two lenses for my kit and am curious about how people feel about them, particularly those who have experienced both lenses. To my analysis (probably of little use to anyone, certainly historically should be of no use to me) they seem similar in focal length, dramatically different in size, not too dissimilar in coverage, and not all that far apart in price. So what are some of the important distinguishing characteristics that might help someone choose one of these two lenses over the other? Or am I missing a lens from one of the other major lensmakers that might be better than either of these?

Experience, facts, opinions, and preconceived notions are all welcome.

Thanks,
LJS