I've been playing the trial as well. I'm level 10 and had to stop myself from leveling. The trial only lets you hit level 14. Which is nice, I guess. You get to see what your travel power will act like and how it works. However, 14 is hardly far enough into the game to get a feel for it. 20 would be a better number. I think that's when you can actually PvP.
I can't really comment on Aion, but I've heard enough to know it's probably not for me. I hear it gets very grindy. I also hear the same thing about CoH/V. However, in CoX I find it interesting. A game where gear doesn't matter for a change. I find it to be refreshing not to have to worry about the constant grind of end-game content.
Either way, I have a Villian on the Justice server.