No familiarity with the Leader, but I just googled and it looks nice, FWIW! It's kind of hard to beat the Mark V Pro for a 631 frameset @ $320. I'd also add that you should consider geometry and fit as well, since a bike that fits will always be the best choice, among three in roughly the same range.

I'm quite taken with Wabi, especially the (unaffordable, to me) Special, but it has a slightly different geometry compared to the others.