Scott Kelby, up until July 2013, was a Nikon-only lover. Canon began sponsoring Kelby training trips. Canon loaned him a 1dx to shoot a NFL game. He became addicted to its AF and fps and fell in love with the ergonomics. He has sold off all of his Nikon gearhttp://scottkelby.com/2014/why-i-switched-to-canon/
I've found him to be a cheerleader, like all Explorers of Light, for the gear he uses, but, mostly accurate. I used to subscribe to Kelbyone training, but didn't renew because he didn't put up new content faster than I was consuming. I just use lynda.com and youtube for training.
I started using Canon when I picked up a used AE1.