The music was not anywhere near mediocre. For one thing it's the first soundtrack where Uematsu had anything approaching adequate synth voices to work with (the FFIV voices are pretty bare-bones and it takes a toll on the complexity of the soundtrack) and he's gotten a lot more skilful at arrangements. The melodies are pretty top-notch as well.

Granted, it doesn't have the consistency of a soundtrack like FFVI's or FFIX's but it's still a solid soundtrack. Most of the tracks are quite good.