I think he Mini is large enough for most people unless you carry a lot. I'm 5'7" and carry one, but I admittedly like the large for work days, so I can fill it up.
There is a great modeling shot for comparison in our original thread. I will try to find it.
I am not petite, but I'm 5'5". The large seemed big when I first got it but now that I've used it, I love the size and I don't think it looks huge on me. If I was running errands or something like that, I would want a smaller bag.