Canon EF-S 15-85mm f/3.5-5.6 IS USM

This is a very good lens. I just opened it yesterday and I won't go as far as to say I am thrilled, but I am very encouraged. The first thing that strikes you about the lens is the build quality. Though it is not up to L standards, its simply the best constructed EF-S lens in the lineup - I would even say it bests the fan favorite 17-55. The lens feels heavy and substantial - you know instantly this is a better lens than most of the other EF-S consumer grade lenses.

The barrel is tight and is not subject to lens creep like so many of the other EF lenses (I am specifically thinking of the EF-28-135mm the lens that seems to find its way on to every non-Rebel as a kit lens) which extend all the way out when you walk a few feet.

The USM focusing is VERY fast and thus far VERY accurate on my XSi.

At 15mm, I've noticed some pronounced vignetting, but the barrel distortion doesn't seem as pronounced to me as others have stated. The center is tack sharp and the edges I would say are very good, but its tough to tell if I'm looking at BOKEH or images that aren't as sharp. I'm inclined to assume its bokeh. I've tested the lens at 5.6, 8, 9, 11 and 16. The edge performance improves the higher the F number.

Fast, accurate focus
Best built EF-S lens to date
No lens creep - YEAH!
Center sharpness
Its aesthetically a good looking lens
Very useful zoom range
CAs seem to be well controlled

Only 3.5 at its widest and drops to 5.6 as you zoom. Wish it were 2.8 for most of the range, but I tend to think the cost would have been prohibitive for an EF-S lens.

If you use the lens indoors and want fast photos, you'll need a flash, you'll need a hot shoe flash to minimize the vignetting at 15mm - Outdoors this isn't an issue

EF 28-135
EF-S 18-55 kit lens

Adorama got me the product in 3 days from the date of order via UPS, very responsive and they were the first big camera shop to have it in stock