It's definitely one of TNG's better eps, although I do think it could use a little improvement. Maddox's threat to remove Data seems like more of a plot device than a genuine problem regarding his sentience, since it is clear he was in the minority even when Data asked to enroll at the academy. And it becomes evident very quickly that fully proving Data's non-sentience would be extremely difficult, so Maddox has to go for the ruling that he is ultimately property of Starfleet.
* shrugs * I think this plot line was done a little better in "The Offspring." But the characters are handled very well for the most part. I don't think Maddox is exactly bigoted per se, but I think he'd be a better character if he wasn't presented as a voice in the wilderness.