The faceted girdles on the long side are thick, there's no denying that. But for my case, I think it's a good thing.
My GF is a bit of a klutz. If you look at pictures of round diamonds laying flat on a table, in a 4-prong setting, the diamond rests on the table. If you look at a similar picture of a Jubilee (one on GOG's site already), the ring rests on the prongs.
I can't say how hard or often you'd have to hit your ring on a desk to chip it, but I think the Jubilee is less likely than an RB or Princess with a more consistent exposed girdle throughout.
Remember, you're usually viewing it from the top anyway.