I played CO at launch, and tried it out a few times over the years, but really gave it another good try after CoX died. I have strong opinions about CO. At its core its a terrible game, and here's why:
1) Stories are utter garbage. It like the head writer was trying to write for a super hero parady game. Everytime you tried to accomplish anything, it constantly reminded you what a big joke this whole thing was.
2) Reward system encouraged inter-player strife. I'm not a fan of the need or greed system, nor am I a fan of "rare bosses" that spawn to drop some retarded loot, as it only encourages players to engage in negative confrontational behavior with each other.
3) Builds were all about tank/DPS/heal. Crowd Control and other exotic defense mechanisms were non-existent.
4) Open build system encouraged Franken Builds, which in a way are not unlike what we have with Sentinels in this game. It'd be like if 90% of the player base on homecoming ran around as Sentinels. Thankfully, that is not the case in homecoming.
5) The stat system was weird and obtuse, and basically rubbed in your face that this was a tank/dps/heal game.
6) It was like someone said to themselves "You know what would be cool? What if we made a super hero WoW clone?" This isn't knock on WoW. I personally don't like WoW, but I respect that other people do like it. I don't see how anyone can make game that out-WoWs WoW, and history has proven out that no one can out-WoW WoW. Take a watered-down WoW and put a super hero skin on it, which is essentially what CO is and....no one cares!
7) Bugged Alerts. To me the final straw, after giving CO another try, was getting into an Alert (which others whom I assume were also CoH refugees) and the mission was bugged! The mission we were on was broken, we tried all sorts of things to get around the bug, but we coudn't, so we had to abandon the Alert. That was the final straw for me and CO.