Any Chance of a comparison between the Sigma 12-24mm and Sigma 15-30mm

Hi all,

Is there any chance that some one could supply some practical comparisons of the results produced by the following two lenses,

1) Sigma 12-24mm f/4.5-5.6 EX DG HSM and

2) Sigma 15-30mm f/3.5-4.5 EX DG

I currently own the Sigma 12-24mm but I really have an urge to try and get my hands on the 15-30mm.

Thanks for any help you can give.

Bryan (BPB)