I got the big size to use for work. The mini is absolutely adorable but I have enough handbags for now (is it possible?).
I think it's a good size though; probably about 14" long, 8" high, and 6" deep.
I think Zappos has a modeling pic of each Quinn if you want to compare.
I ordered this yesterday...I'm so excited! I've seen it in person and it is a decent size. It's definitely not mini. Seems like a good medium size bag that could pretty much hold everything you need as long as you don't drag the kitchen sink around with you. BTW, if you are interested in getting it, shopbop has it and you can get $50 bucks off. Go for it!