*raises hand* I was there for day-1 as well, and remember the massive cut in power (and exp!) that everyone got. It definitely made the game feel a lot more sluggish and annoying, rather than superheroic. Even in the teens you'd be fighting random street thugs, and 3-4 minions could make you have to struggle to take them all down. Imagine a fairly experienced superhero struggling to take down a couple of muggers. It'd be embarrassing!
The villain groups were far too jokey and full of puns, and the game clearly didn't take itself very seriously. Which means players didn't either.
The way they did powers was interesting, but it tended to promote a very "best at level" mindset, where you'd take the single best power for that level, or level up a bit more then completely rebuild your character to take the newest, best power, dumping the old one in the process. Too many powers were overly-weak and not worth taking at all (the pet powers were all notoriously bad), and other powers (such as super strength's "uppercut") were far too powerful compared to anything else you could take. For a game with tons of power options, you saw a lot of very similar builds running around.
I gave it a few months at launch, then got bored and went back to CoH. I really wanted CO to be a good game. I really did. I played the tabletop Champions game for years and years, and when CO first announced I was giddy with the idea that, since they had bought the actual Champions IP, that it would be somewhat similar. That you could build a character concept and run with it. Instead, we got a watered-down, powerset-limited mishmash of a game that had no real heart.
I've popped back in from time to time to see how it's doing, but man is it lifeless. And there's not really that much more content than was there when it went live. The fact that it's still around when CoH got shut down by NCSoft still angers me. To this day I refuse to buy any product that NCSoft puts out.