I think that comment is referring to the framework / server, which is quite fast. Heist is a templating system authored by the same people that was not intended to be fast (though now it is). It is somewhat confusing, but I don't think the work they did on the framework/server (which is totally separate from Heist) should be discounted as "fast enough on the first try."
Correct. We always marketed Heist as a more experimental part of the framework as a whole. The server and associated API was initially our primary focus.
"When we originally wrote Heist, speed was not our goal." from the link submitted here
Feel like a contradiction, couldn't they just say that it turned out fast enough on the first try?