Spence is not close to ready at the time being. Defense isn't sharp enough. And he would lose the biggest advantage he has at 147 , which is his physical strength. Canelo is just a better boxer all around. Even disregarding size, canelo would still win just off superior skill set. Brook stunned spence a couple times with straight rights, which is canelo's best punch. Spence is just too predictable for canelo right now. His whole style plays right into canelo's hands. Maybe in a couple years as spence improves that could be a much closer fight, but right now spence doesn't have the tools to beat canelo. I think spence would take the fight cause he's a warrior. but no chance his team would do it. When you hear Derrick James talk about canelo you can tell how much respect he has for canelo's talent. Spence should focus on cleaning out 147 then focus on 154 and 160. It's a different ballgame at the higher weights.
Imo they are close to each other regarding the skill level but with the main point I agree. Spence just started to shine in 147 and while he is a big welter he is still a welter not even a 154, at the same time Canelo became a true middleweight. The style matchup is similar to GGG vs Canelo though I think Spence would be a little faster than GGG was in exchanges so offensively he would have more success in the middle of the ring but even though his chin seems good currently there is no guarantee (actually it’s not likely) that he could take the shots Golovkin, a natural mw took (cause Spence would get hit too).
The kind of fighters giving Canelo problems
1: rangy boxer with good footwork who doesn’t carry himself over
2: a guy who takes his punches and can force the pace later in the fight as well when Canelo gets tired
Spence could be the second category in a few years if he grows into the proper weight but right now I don’t think so, not because his pace but because I doubt he could take those punches now as Golovkin did. Let him grow into that weight and this could be a super fight around 2020-2021 if both are still close to their prime by then