Most people struggling with soft images are those who do not know how to use the advanced AF system yet.
I was definitely one of those people, and spent a full day just learning how to use the different AF modes. It paid off.
I totally agree! I spent my day yesterday w/the camera tethered to my compy, dialing in the MFA, as well as just reading up on how to use each separate type of autofocus. Coming from 5dii, all I did was center-focus and recompose (like most). The abilities opened up to me (I shoot weddings primarily, but this also applies to walk around everyday stuff) by the new autofocus alone are worth the upgrade to me. Add in all the other perks, and I am more than "delighted." I have absolutely no complaints w/low iso performance - I am by no means an authority on the subject, but I have an epson 3880 printer, and printed some fairly large shots yesterday, and am very pleased!