Since Christmas I have been shuffling/selling/buying bc I knew I wanted to upgrade lenses (I used to have the kit and 50mm) and now am about to pull the trigger(s). I now currently have BNIB Sigma 30mm 1.4 that I am sending off to Sigma for calibration tomorrow - but beyond that I need to make some purchases. I have about $1100. Both options below are approximately $1100.
Option A) Add new Sigma 10-20mm + new Sigma 17-50mm
Pros: Great lenses from what I read, long warranties, my gear will then cover fast prime, UWA, and zoom
Con: Will they both suck at focusing like the 30mm I just bought?
Option B) Add new Canon 17-55mm + hood
Pros: great lens
Cons: dust/1 yr warranty, price, I only get 1 lens
Don't assume Sigma will fix your lens. I'd retun it. It hasn't been easy at all dealing with them and their repair department.