I personally disagree with ulikey, I find that the small just isn't good for me. I don't think the large handheld gets in the way at all.
You can wear the large and small over your shoulder with the long strap, however to wear the short straps over your shoulder, you need the large.
I've used the long strap maybe once. I much prefer wearing the short straps over my shoulder or in the nook of my arm.
I would recommend that if you can, go and try them on. The size of the Sophia definitely isn't one we can decide for you. It's so dependent on your body type/height.