Plus with a name like Ego he really couldn't be anything other than evil.

Oh yeah, definitely. He was a fascinating character, and I think if I see the film again, it'll be interesting to watch his scenes again knowing what his motivations really are. Despite the stagnation, I think the film did a good job of conveying the not-quite-right-ness of Ego's planet, between Gamora's suspicions and basically everything with Mantis. They just kind of lingered on it for just a bit too long. *shrug*