Funny that you should ask because I was just thinking about the same thing. My husband surprised me with the large bamboo shopper for my birthday this month. It's absolutely stunning! But, I haven't used it yet because it seems so big and the smaller shopper seems too small. I was thinking of exchanging it for the Boston, but I'm a bit afraid of the sagging issue with the boston shape. I hope others chime in to your question.
And one will feel better, as well. Also, if you decide on the Boston, you can always get (or make) a shaper for the bottom, which will protect the bottom, as well. Both are lovely and timeless.I'd go any try them both on and then decide. One will look better on you
Just wondering which one did you finally get and how do you like it?