I think more than just a "fantastic switch defender," we need a long, rangy, switchable guy who can be solid both on defense and playable within our offense. That means someone who can create/finish/shoot sufficiently not to be played off the floor. The Clippers handed it to us not only because we couldn't hold up defensively (though that certainly was a problem), but because almost everyone they had that could switch defensively was also a decent offensive threat (esp. with Mann having the series of his life).
Whether Herb Jones is someone that Quin will trust to play offensively, I'm not sure. He might be. But he might also be Ronnie Brewer unplayable on offense during the playoffs. I think I'd take him over Greg Brown, however; ... hmm -- close call on that one.
I will say that, shooting (and already being a senior) aside, I love what Herb Jones does as far as playing winning basketball.