I like reading different opinions on sizes - very interesting. I have both sizes and I am one of the few that prefer a 35. For me, it depends on how I see a bag being used - my idea of the perfect look for a bag. The Birkin is a workhorse - it's a tote style in a classic design. For me, it's not meant to be dainty at all. That's why I prefer the size 35. I am about 5'4" and I love it best with high heels and great pants for work - I would never carry a Birkin to a wedding or like occasion. So even though I like the weight of the 30, it's too pretty and cute for me to be used as a rugged workhorse - the way it should be in my mind. If I want to look ladylike and pretty as opposed to an executive look, I'll reach for a Chanel flap or the Lady dior, or even the kelly - those have a slightly different feel. I think smaller bags are really popular now and are making people reevaluate bigger sizes, but I think the 35 will always be classic..