I admit it, first time I played this game I found Locke very boring, because his sprite wasn't as colorful as most other characters and his physical attacks sucked - so I actually left him out and used Edgar, Sabin, Cyan and Gau.
I absolutely loved those characters back then, especially Gau's countless, versatile Rages and Edgar's overpowered Bio Blaster.

...but yeah, Locke is awesome if you use him right; dual long range weapons in the back row with the Thief Glove equipped = sexy Locke.