In my experience, the best and worst managers are non-technical, where technical folks are middle of the road:

Bad Non-Technical Manager

Either incompetent or evil. Does not understand technical discussions, will pick and choose the parts they like, and hold you accountable for their misunderstandings. Promises superiors the impossible, and expects you to deliver. May or may not have pointy hair.

Bad Technical Manager

Thinks he is boss due to superior technical skills. Is in fact a marginal developer who hung around until promoted. Limited management skills, gets pushed around by other managers, is powerless to go to bat for you. Delagates administrative tasks. Still wants to develop, meddles with technical decisions, even though he is years out of touch. Usually has a basic idea what is possible.

Good Technical Manager

Got coerced into management, to fill a need or fit him under the pay scale. Knows his stuff, will dive in to help with the technical work if necessary, but allows his people to find their own solutions. Natural management skills, but not interested enough to learn to traverse corporate politics well. Often has to fight to get things done. After a few years, may turn into Bad Technical Manager.

Good Non-Technical Manager

Actually wants to be a manager. Acts as facilitator and arbiter, rather than boss. Insulates group from administrative tasks. Understands group members strengths and weaknesses, delegates technical decisions. Often promoted, or drummed out of company.