Rory's the standout candidate
We've discussed him before, twickers, and I still agree with you.
The problem for Stewart, though, is that a lot of grass-roots Tories still see him as a Remainer, and therefore unelectable. I saw a very interesting BBC interview yesterday with several local Tory party chair(wo)men, and most of them effectively said that. Also, C4 News ran a piece today about claims that the Tory Party's recently been inundated with applications from ex-UKIP members to swing the leadership vote behind a hard-line Brexiteer...
That said: I was discussing this earlier today, and I still hold that if Stewart (and/or one or two other candidates) makes it past the first round (and Stewart's fairly confident he will), then the TV debate shortly afterwards will be very interesting, and IMO a potential game-changer. Expect a few very articulate, reasoned, speeches and some home truths, while Boris will either bluster throughout or (more likely) not bother to turn up at all...