I have been playing with the thought of buying this lens. My experience with Sigma has not been good but I kept my sigma 150 macro as the IQ was great and almost always use MF.
Please reply if you had to get multiple copies or had af issues. Ive searched the web and forums but wanted to get a different feel.
I love it, with the caveat that autofocus performance is not as good as
with the Canon 50/1.4 but it's still workable and optically it's great.
I may send it to Sigma sometime to see if they can tweak the AF performance,
as I'm reading that many users of new copies are getting great AF.
Perhaps Sigma has a real fix now.
Anyone interested in great f/1.4 performance should consider this lens.
My copy - overly soft and glowy, focussing good at short range, useless (ie +/- 2ft) at 10ft or more. Performance worse than Canon 50/1.4 in all regards. Returned it.