I think it's a big mistake to think that Jon will be faster than Gane here. You have one guy moving up from LHW that may or may not be used to carrying the extra weight. Jon was never even a blazing fast LHW. He used distance/reach, timing, variety of strikes, etc. to get work done. Remember DC was landing a lot on him even in their second fight until Jones landed the head kick. With Gane, you have a HW who moves like a smaller guy. Fluid and pretty quick, not lumbering at all.
I do agree good chance it goes the distance. I just think Gane gets more done. And given that he's +140, it's an easy bet for me. Not a lock obviously, of course he could lose. But the value is there.