hi, i'm confused between sigma and canon... 85 1.4 sigma or 85 1.2 II canon... canon one is far more expensive. but is it worth buying? i own a sigma 70-200 f2.8 APO DG MACRO HSM II, which is half the price of canon 70-200 2.8 and equally good (i'm not going by the reviews, i personally tested both the lenses at canon center) may be i have a really good copy of sigma. what are your thoughts on this new sigma prime? has anyone tested it against canon? i'm using a 7d body.