On the whole I agree with stephen the personnality is the most important.
However my experience lead me to think that technical managers tend to have a better understanding of the work to do and hence make better choice when they have to choose priorities, estimate the developpement time, make the best out of other programmers...

I had 'commercial' managers who told me :
'What 4 days ? Rewriting this (entire) programm for only 4 (6) platforms will take you 4 days ? Just skip the tests, you'll have 2 days...'

Usually an technical guy will understand and rather say it like that :
'Ok just drop the less important features for the moment, I'll try to get one more day saying that the 5 others platform weren't in the specif. But please double check your test, it must be clean.'

It may seem a little bit exagerated, but it's often like that for me.

And usually good (tech) manager don't tell you things the way they didn't like to be told when they were only coder and that's a REALLY good thing.
I'm one of those who thinks that you can say almost anything, but that you're better listened when you're not hurting your listener.

"Only Bad Coders Badly Code In Perl" (OBC2IP)