i know this is canon lens only subforum, but since sigmas are reviewed on the site i just have to put it somewhere

since i didnt notice this lens being mentioned anywhere else on the forum, i suggest you check slrgear or lenstip reviews of this lens. its has excelent build quality, its vey sharp, has low ca and low distortion and good af
and it has 1.8 troughout whole range, at only 800 bucks

i've only just found out about it so i'm posting this now
a lot of people think this lens is a game changer and that its going to have pretty strong impact on market, possibly reducing prices of currently available lenses (especialy used ones and primes in that focal range)

also, if iturns out that this lens is really that good, it will be interesting to see response from canon and nikon, cause (even with shorter focal range) this seems to me like the best possible upgrade for some who wanta to drop theor kit lens