I think I'm about your size based on your description, and at least DH doesn't think it looks too big on me. He also likes the Gigi, but not the Thompson hobo, Elisa, editorial Zoe, or bags like that so much on me. I think it's a satchel style vs a hobo style according to him.
Now that said, the Peyton is NOT a tiny bag. Somewhere I do have the dimensions I took for momofgirls, and will try to post later. Keep in mind I carry small laptops...like the Asus Eee or Acer Aspire will fit fine. The small Macbook MIGHT...I need to try my friend's and see, but it looks like it might just based on seeing them at the Apple store. I'm not sure, though. I always have a ton of more room to spare with mine.
The Peyton also slouches a LOT when you carry it and no packing materials. I keep a layer in mine to kind of keep the basic shape, but it looks much smaller carrying it than stuffed at the store.
It all depends on what you think is a big bag or too big of a bag. The funniest comments I read on here were some people thinking the Bleecker woven hobo is huge, and I bought that and time it slouches, I'm like "where's the bag", lol! Yet I like the Bridgit, which is small. So it's all relative and depends on your perspective and what type of bag you like to carry! I think I compared the Peyton with the two Lily satchels...I'll try to find the photos and post them.