I'm happy with both cockerels and pullets (though I've only ended up with two of each, after various troubles getting the incubator to hatch anything at all).
So here they are.
power and vigour.
They're also of the right temperament. In fact they're better than many male birds I've kept, as I'm having no great trouble keeping both cockerels in the one pen. This may change as they mature, but basically they ignore each other most of the time. And needless to say they don't show any signs of turning on me, nor are they what I'd call 'too tame' (often a precursor to human-aggression).
They're not quite 19 weeks of age, and one of the pullets laid an egg today, so that's pretty good going.