Prince Buster described Rocksteady as "the summer season of ska" and this is born from the fact it is more slowed down and soulful than its cousin. This is illustrated best by the hilariously named GAYLADS and their track SOMEWHERE OVER THE RAINBOWS END. Other tracks which live up to the mark of quality of Trojan are DERRICK HARRIOT'S LOSER and JUSTIN HINDS AND THE DONINOES' HERE I STAND. Having said this there isn't a track for which I wouldn't steal if I didn't already have it.
In conclusion if you aint got it - get it.