Wallin for sure. You know, Crobox, you enjoy boxing a lot obviously, I feel bad that you put so much time into HW. You should try following just a few guys in the lower weight classes, it'll fill up your time and leave you feeling like you're waiting a lot less.
Actually, I'd pick McKean. They're both southpaws, so Otto's one advantage goes up in smoke. Demsey probably has the better gas tank and the higher workrate. So, McKean would most likely outwork him and win by 115-113 or 116-112 type scores.
I think Wallin should be the slight favourite but I tend to agree with this. Wallin probably doesn't have the power to keep McKean from taking the initiative which Otto is sometimes all to willing to let go.
What about the Plantic boys? Doubt we are going to see them rise to status of the legend in your avatar but Luka is one to watch for sure.
They are both pretty average. I would go towards Wallin winning a points decision akin to his win over Brezeale. Wallin has a lot more experience now especially over 12 rounds. I hope Wallin can fight a top 20 heavyweight soon.