It's probably the face; prominent cheeks, roundish head, button nose, large expressive eyes, appealing curves and reverse curves, being a cat (the internet loves cats, this is a fact)... all that good crap.
Phew! The changes are quite subtle; I had to go back and check the differences!
Probably the part that sticks out most to me is the ears, and I prefer them this way. Without casting aspersions I've always seen the big, droopy cat ears as a very anime feature but I feel these are more in the spirit of Sarah.
Heh, well there's not much more I can change without her becoming totally different. I do appreciate you actually checking other the older models, though!
Oh yes, the ears. With them up like that, she's around 20% more perky-looking. They're not big and hard to manage like before either (previously, I often opted to only draw one visible ear from profile or 3/4 view).
It's kind of cool that you mention Sarah's spirit. Having her essence alluded to makes me feel like I might be doing something right with her!
Yes, absolutely. "Cat" would make it more of a Sonic character anyway. I like it when they have full names because then the rest of the family can either also be really funny like her dad's name or not make any sense at all!
I think I liked her old design better. Not there's anything wrong with this new one, but I preferred the rounder look of the older models. Of course, I have a preference for older styles in general, so that may just be me suffering from nostalgia.