i have an incase and i definitely can't open the screen as far as i'm able to without the case on it.
the speck doesn't have that problem, but the speck is pretty different in design anyway.
the incase doesn't cover the whole computer, it leaves a little big exposed at the rims.
and also, the sleep light / sensor is not covered, there is a hole to allow you to see it. (i'm not sure why, since it's seethru anyway.) but the speck has it completely covered.
and as for the black, it should look black. the speck's black case looks black, but the apple looks deep purple. the light that shines through it, if white, looks purple. but the case itself looks black. not sure about the incase though.
either way, you won't be disappointed. it's a good case.
it does it's job well, and it feels nice.