Well, after about 7 weeks, my 24-60 has returned better than ever. Sigma recalibrated the front focusing lens and replaced the front element (that one surprised me). I forgot how good the optics are in that lens. That lens is a testament that Sigma can and does make outstanding glass. Yes, Sigma has QC issues, but I think more people need to go after their glass as they are an outstanding alternative to Canon's glass (especially the double standard of when the Canon misses focus, it needs to be taken back; whereas for 3rd party you need to return it and get better glass). For me, the only reason to upgrade would be for a better AF system, which I don't need right now.



