Well, first of all, I have to say that I'm biased towards the red Jumbo (and flaps in general), because I have and absolutely LOVE it to pieces... I keep the inside straps tied with a white Chanel ribbon, and have no problems with it... plus, the bijoux chains just make the bag feel so much lighter and easier to carry than my other flaps.
If I were you, I wouldn't keep the red Jumbo based on the fact that it's so highly sought after, because who cares about that if you own it and never use it, KWIM?
Just looking at the two bags from a neutral standpoint (as neutral as I can be anyway haha!
), I prefer the look of the Jumbo. I think the hidden chain is more limiting in what you'd wear it with, cuz I see it with casual/casual chic kind of outfits v. the Jumbo which I think can be worn with more and is more versatile.
Of course, it's your opinion that matters the most in all of this!
Maybe you should bring your red Jumbo out with you to the boutique wearing the clothes you'd normally wear (this is also assuming you don't plan to sell it as a brand new, unused bag) to try on the red Hidden Chain bag... that way, you can have both bags in front of you, try them on, and see which one is more YOU.
Good luck girl!