Outside of DC, Jones' toughest fights have been the bigger guys. He loses his size and reach advantage. I'm still leaning towards Gane mopping the floor with him unless Gane fights gun shy which is entirely possible.
Is he though? The heights for everyone seem to move around an awful lot. Depending on when and where you check, Gus is 6'4 or 6'5, and Gane is 6'4 or 6'5, Shane Carwin has been 6'5 and 6'2, Anderson has been 5'10 and 6'2.
Jones recent close fights was due to a lack of motivation and preperation. He is highly movtivated and maybe more prepared than any of his fights. . Gane speed is the only thing that can give Jones problems. Jones will stand up with Gane in the first round just to see if he can hang and then towards the end of the 1st or beginning of the second round he is going to take Gane down and finish him.
Jones has historically struggled with taller and longer fighters, but it could be a whole different situation at heavyweight. We've never seen a 245-pound Jones driving forward on a takedown, and we don't know what kind of damage those kicks and elbows will do with that extra muscle.
Fight is so difficult to handicap because we have no idea what the combo of mass bulking/more than 3 years off will do to Jon, for better or worse. He could be a wrestling/GNP beast that takes Gane down and pounds him through the canvas. Or he could be too slow to close distance, slower and less powerful than Gane in his strikes, and get picked apart by the guy used to carrying his muscle mass. Having never seen Jon spar, let alone fight at the size he is (looks huge in pics I've seen) I can't feel comfortable picking a winner.