Now watching: a Longplay of SMW 2: Yoshi's Island. We need a kind of prehistoric ponification with baby Princesses and a friendly Dragon who helps reunite them :3

Really, comparing Twilight and Trixie is like comparing apples and oranges; they're proficient in different skills. Twilight's specialty is what I'd call practical magic, while Trixie's is performance magic. The problem wasn't that Trixie was incompetent, it's that she was hyping herself as having skill in an area she wasn't skilled in. It's like someone who's an excellent actor using their skill to pass themselves off as a doctor and then being found out when they actually try to do something related to medicine. The fact that they're actually a terrible doctor doesn't make them incompetent as an actor. Trixie's an excellent performer, but she used that skill to pretend to be something else, rather than just being a performer.

As far as having her come back...it's a mixed bag. I'd kinda like to see her again, but I get the feeling it would trigger a massive Hype Backlash in the fandom. Everybody has their own ideas of how Trixie "should" be handled, and they're going to complain if it doesn't match up.