Hard to say. Not only do we know what Cormier can do at HW, but we know he can put on the necessary weight, carry it well, and be successful. We don't know if Jones can compete with the HWs and just put on minimal weight. We don't know if he can add size if he needs to, and still be effective enough. We don't know if he can deal with the guys who are bigger than he is. With Jones it is a complete mystery.
But I'd like to find out for sure. I would love for Jones to come back and move to HW. I might like to see him in a Gustafsson rematch, or maybe against Rumble. But I would rather see him against Werdum, Velasquez, JDS, Overeem, Browne, Miocic, Hunt, Mir, Bigfoot, or even Roy Nelson than anyone currently at LHW.