I'm surprised that so many people think Uhura had no personality. She had bags of personality. People bang on about one line that was originally written for Janice Rand but forget that in that same episode Uhura was placed in charge of a security team. She was a competent electronic technician, professional, extremely intelligent, spirited, and was not afraid to speak her mind.
I agree that 70% of her appearances were limited cameos but there was an awful lot that Nichelle brought to the role when given other stuff to do.
In the context of the sixties, Uhura was pretty cool. She lost out because they called in Spock to deal with any even slightly sciency communications issues. If Shatner and Nimoy had not hogged most of the limelight, Uhura Prime's skill set would have been plenty broad enough.