RoM is very similar to WoW rather than runescape.
As mentioned:
RS - Skills, grinding, one specific gear, can't make it better, game is based around money
RoM - Fighting, quests, instances, gear is modified, always able to get a little bit better.
I enjoy RoM much better, less downtime. But for a game after a night out, RS is what I pick, nice and laid back