Had a crack at it last week for the first time. Never felt so guilty about hating a game before...
I remember at the time of release there being a bit of controversy with regards to the players interactions with Trico. Having played a fair chunk of the game before abandoning it, I can safely say that my experience is perfectly in line with those criticisms.
Trico's design from a mechanical perspective just doesn't work as it should. I GET that he's meant to be this untamed animal that rarely follows direct orders, but that clashes so often with how the rest of the games designed. Often times I'd abandon any attempts at getting him to boost me up to a specific ledge thinking that it must be the incorrect path to take through the level, only to go back there after failing at everything else to discover that it was in fact the right ledge all along, and the game just refused to acknowledge my button prompts in a timely fashion.