A weekend e-ring is something a bit more blingy than daily wear. I think size is unique for everyone. My weekend ring is a 7.5mm ACC, it faces up like an 8mm round and is plenty o' bling for me. That being said I love seeing the 2+ carat "honkers" around here.
My ring should be in next week, very exciting! I'm pretty patient about the wait until it is 3-4 days before, then I am too excited for my own good.
I'm actually not going to wear this little guy with my e-ring, I think it will overpower it. Maybe if I had a 4 carat emerald cut, I would rock the Kim Kardashian look.
As far as bigger than 10mm: did you mean a 10mm round? I love BIG, but I like 3+ carats in fancy shapes emerald cuts, asschers, cushions. It's a personal preference, but I think it compliments my finger more.