Just based on what you said, I'd go with the Jumbo.
I have a M/L in the combo you wanted (black caviar, silver hardware) and I went with the M/L because I'm a small bag person at heart (my M/L is the perfect size for what I carry on a daily basis). But if you're a person who likes larger bags, I think the Jumbo would make more sense for how you use your bags. If weight was a huge issue, I don't think the bag would be as popular as it is now. And if you're used to carrying a lot, I don't think all that weight would matter much.
I have a M/L in the combo you wanted (black caviar, silver hardware) and I went with the M/L because I'm a small bag person at heart (my M/L is the perfect size for what I carry on a daily basis). But if you're a person who likes larger bags, I think the Jumbo would make more sense for how you use your bags. If weight was a huge issue, I don't think the bag would be as popular as it is now. And if you're used to carrying a lot, I don't think all that weight would matter much.