Back to the real world. I trust the observations of a user over a tester.
Bryan Carnathan has the credibility of being an actual photographer, and his reviews are more focused on his user experience with the gear and less on MTF charts. He's a bit pro-Canon and tends to see the best in their products (lots of enthusiasm for new offerings), but his insights from use and personal anecdotes of how his gear gets it done or lets him down is valuable. He's also very good at sniffing out odd problems with gear (e.g. the Sigma 50 Art AF semi-inconsistency) and sharing his work behind those findings. So I don't look to his site for hard data so much as a global user read on a product, and he's very good at it.
I'm a big fan of all the good stuff at his site, and he's very approachable to answering my questions.
I know that about Brian and that is what my comment was about. Brian = user, DXO + tester.
I very much trust Brian's reviews and views. He was the one source that I went to when I first started with DSLRs for lens and other attachment reviews. He still is. His reviews are the most in depth I have found and I was very much waiting for this one. It is still a work in progress from what I have read but it is none the less the best out there IMO.