18-55EFS -> Sigma 18-50 F2.8

[Tomsk]

I have a 300D/Rebel with 18-55 kit lens.

Is the Sigma 18-50 F2.8 a worthwhile upgrade?

I have to photograph a wedding in a couple of months and I can't afford a 17-40L
I already have the Canon 50 F1.8, Sigma 70-200F2.8 and a 550EX

I'll be upgrading to a 20D (or it's replacement) in about 10 months time (Christmas ;) )

[Bodog]

I like mine. Here are a couple reviews:
http://www.fredmiranda.com/reviews/showproduct.php?product=232&sort=7&cat=37&page=2

[ron chappel]

Here are some more comparison reviews with various lenses

http://www.pbase.com/joemama/sigma_1850__28
http://www.pbase.com/miljenko/image/37156215
http://www.pbase.com/kazfujieda/lenstest&page=3
http://www.pbase.com/miljenko/ccrm_bokeh_tests