I got my S10 in Prism Blue as well, on Friday ...
I had to find a case for it right away as1. it's very slippery, 2. it has the curved edges (which I DON'T like) ...
I have been using Otterbox Defenders for ever, just really good cases and working outside every day, I think its a must to have the protection.
While the S10 is larger in overall size to my S7, by maybe a 1/4 inch, when I put the case on it,it really doesn't seem bigger ...
the S10 is slimmer than the S7 I believe and narrower as well, so those things probably make it seem smaller, with a larger overall screen coverage !
Now that I have the case I wanted ... had to really search for the color, didn't want Black and the other option most places was Purple/Pink ... I don't know what color they actually call this one I couldn't find at the BB or ATT stores (or anywhere else) (yes, I could have ordered it from Amazon and had it like Tuesday, but didn't want to wait ... its a blue/green/aqua type color.
Overall, so far after about 30 hours, I'm liking it very well.