I've been so happy to play with Lucifer again, since the latest patch in May seems to have sorted out the issues I used to have with him causing frequent CTDs. I've only been playing for one evening, but I can't overstate just how nuanced, thoughtful, and uniquely enigmatic he is as a follower, and as a character. He's incredibly aware of his environment, his opponents (he'll say different things if we're fighting bears, trolls, bandits, mages, and even, really, skeevers!), and the finer points of the quests I pick up.
He's the only follower I've tried who actually comments on that moment when the Greybeards shout down to you from High Hrothgar when you're near the Whiterun stables; all followers, vanilla or custom, will look around at the sky in that moment, but Lucifer actually says something about it. At High Hrothgar for your first trip, he actually quickly comments that he's going to get out of your way so you can do what you need to, and runs behind the Greybeards. I laughed out loud when he said there was no way he was carrying me up the mountain if I couldn't make it and mumbled "fatty" under his breath, just adorable.
Just wanted to express my appreciation to you, Alex, and I'm looking forward to the rest of the journey. :)