I actually just read the Legacy comics and they're pretty good. Though the issues starring the side-characters and not Cade were vastly less interesting. I wish they just did those stories are sub-plots rather than devoting entire issues to them.
LOTF wouldn't have worked as a trilogy because spoiler's turn to the dark side would have been WAY too rushed then. I thought they handled that character evolution really well. It was just in the last two books that everything fell apart.