Mika was the name of one of my best friends in elementary school. We always pronounced it as MEE-ka. I think it's a very nice name, although I'm kind of biased :) Since my friend was a girl, I prefer it on females. I met another girl named
Mika last year.
I agree that
Mieke may cause pronunciation problems in the US. In fact, when I looked at it, I had no idea how to pronounce it.
So, yeah, I like
Mika.