Jon Winslow definitely left his mark on Exodus Books. Mostly a force for good, he could occasionally become a dark summer storm with little or no warning. But even summer storms are good in their way, and we'd probably all agree we miss Jon's ability to grapple with tough issues in a way that was never belligerent or belittling.
As for his favorites, they're just as quirky as the man himself. This is meant to be endearing, not off-putting—here's a guy that loves a Catholic like G. K. Chesterton, a Puritan like Jonathan Edwards, and a charismatic like John Piper simultaneously. It's this ecumenical streak that allows Jon to make bridges between people and traditions, and to come off as warm and caring.
Of course, everyone who knows him well also knows about his cantankerous side. He'd probably use a different adjective, but it would be less charitable. Ultimately, you can't have someone passionate about the Gospel of our Lord Jesus Christ who isn't also a bit cantankerous, at least by human standards, and we offer his favorites with confidence in his good judgement.