There's been a lot of recent debate about topy soles on Goodyear-welt shoes. The argument against it hinges (to my understanding) on the possibility that the rubber sole would trap moisture inside the shoe, which might cause the gemming to decay.
A blake-stitched shoe uses a stitch that goes through the upper, insole, and outsole, so there's no gemming. I have heard, however, that there's a higher chance for water to get inside the shoe through the holes from the stitching -- leaving the wearer with wet feet.
It seems to me a topy could prevent that, and the concerns about gemming failure wouldn't apply. That said, would there be any other issues I'm not taking into account? Would it cause the stitching or the leather itself to decay? What about blake/rapid construction?