varchar or nvarchar

Question

I am storing first name and last name with up to 30 characters each. Which is better varchar or nvarchar.

I have read that nvarchar

Answer 1

on performance:
a reason to use varchar over nvarchar is that you can have twice as many characters in your indexes! index keys are limited to 900 bytes
on usability:
if the application is only ever intended for a english audience & contain english names, use varchar