Ive probably spent around 25-30 hours in Champions Online now and I´m already starting to feel the burn that shouldnt come for at least another 100 in an MMO. 
I´m probably the complete opposite of most people now but I´ve come to realize that I actually like my MMO´s to be set in a Fantasy-like world. People might argue its done to death but forests, green fields and fantasty creatures are actually vital to my MMO enjoyment and this is clear to me now. Furthermore I´ve only seen 3 zones in my total playtime so far.  
If you´re going to keep people leveling you have to keep the environments varied. A super plain desert envirorment, a winterzone that dosent really feel that wintery and a major city is all I´ve seen so far and jumping back and fourth between these zones to keep doing the same very imbalanced quests takes its toll. 
The quests are still, often easier for some builds of classes and zones have enemy groups so extremely close together that you keep dying if you´re not doing stuff exacly right. Its not always clear wich route is the best to take to the quest if you dont have flight and I´ve run into several quests that are bugged or that seemingly lacks the objective you´re supposed to complete. 
Rubberband lag keeps making me dizzy all the time and the framerate keeps chugging along at very low speeds stacking it up against me with the glitching friendslist and completely plain AND unbalanced PvP.  
The crafting system is confusing and poorly explained and most items you get from loot just seems like the last one or dont offer any kind of usable stat in the long run.
 
I´m really not hating the game tho. I´ve played enough MMO´s to know that the launch is always glitchy. But there has to be something there that latches on and wants you to come back. 
I know its hip to hate on WoW these days but man, they really nailed it with creating a good enough world with a good enough engine to keep you coming back in its early stages. 
CO´s enviroments are so extremely subpar when compared to that game that I really shouldnt make that comparison at all. 
The fact that I´m not really THAT into superheroes and comic books might also have something to do with why I play shorter and shorter sessions of the game but I really thought there would be more to the game. 
Where is the carrot in this game? because I can´t find it. Leveling and looting dosent do it for me in this one and questing feels like more of a choir than ever. 
I´ll probably keep going at it for a while longer to see where my character development takes me but I dont feel the motivation all the way. 
Some part of it must also be the fact that if you have real life friends playing an MMO it gets much better. As it stands now I´m not doing any socializing at all when playing and comparing that to leveling with a group of friends is like day and night. A Social grind is 10 times better than a mechanic "stare at my screen" grind.