If you wear polarized sunglasses you will have difficulties using an EVF. There is a cancellation effect that makes viewing the whole frame well pretty much impossible. And I'll have to say that when you are in a dimly lit convention center, even with an optical viewfinder I think you'll find composing a photograph easier if you are able to get your eye close enough to the finder to see the edges of the frame.
Just a public service, education posting. Sunglasses. Hmmm.