I hired a grumpy, cynical systems administrator who often spoke his mind at inopportune times, but I'll admit he was head and shoulders above every other candidate in terms of technical ability. And he was diligent.

I liked him. I liked him in spite of his shortcomings.

In general I tend to make large allowances for people of strong technical ability. It's not a conscious thing -- they do good work, and they're effective. Sure, they may be brusque: yesterday one said to me, "No, you're wrong, that's not who it works." He couldn't be bothered to sugarcoat what he was saying. But I like him -- he's good.