I like the Tiffany - I think think the Bulgari looks bulkier and lacks finesse, but that's just my opinion. It really depends what sort of look you're after.
The size fits normal. I have tried it on before (when we were on vacation in the Caribbean tax free) and prefer the wider width band Bzero in wg and just my luck, sold out of my size but many size available in yg. Rose gold would be nice, good luck w/t your decision