I don't see how a gal can have one and exclude the other. They are like cousins. Same genetics, but unique characters with notable differences. The Havana is a slouch bag. No getting around it. It is my favorite "throw on and go to the movies" bag. But, I like the Yves (which is so close in size) for several reasons:
1) The Havana's front pockets are so small they do not really carry much - leaving the one zip pocket in the back to carry the "outside load". The Yves has those 4 spacious "easy to slide in" pockets like that vintage HH one (the Nico?). I like those outside pockets better
2) The Havana has studs. It has zippers. It has zipper pulls with studs. To me, it is the more fussy bag. The Yves is a bag to show off leather. I think we will find that HH used a great leather on this bag... because it is a bag that is all about the leather. The only hardware on it is the turnclasp and the little detachable tassel. I am excited to see what HH calls "a gorgeous rustic leather".
3) The Yves has the foldover fish-mouth (as Gingey calls it) opening of the Havana. I think the photo HH has of it has it stuffed with tissue beyond the drop of the foldover so that it doesn't get to "slouch" in the middle of the top like the Havana's picture. I think it will slouch enough that if its owner doesn't want to turn the clasp, they won't have to.
4) Zoom into the Yves clasp. It is not the fold-down turnlock clasp of the other bags. It is a smooth oval doorknob-type turn.
5) The strap rocks on the Yves. That is the Havana's weak point. The adjustable sections on the Yves strap looks so much more functional. Closeup of strap:
6) I really would love to see the bottom of the Yves bag. It looks a bit more framed than the Havana. As Jenn said, a touch of a bucket bag's base. I think that will make carrying chunkier things easier. When I carried large, chunky things like cameras and boxes with lenses, my Havana got "pooches" (dimples) along its side that I would have to smooth out. A more defined base would have helped with this. I think the Havana is a great bag if you are carrying a lot of smallies, but large items can be a bit difficult to the turn of the leather at the bottom of the bag.
That's my comparison of the two bags. I think it would be great to own both. I only hope the handbag fairy brings me a BIG deposit of cash under my pillow before the sales. Because all my early-season money will go to the more structured bags first: Trophy, Biblio, Franklin, Burke... ouch, I am in financial tizzy already!