We drink those at home. You're right in that they're refreshing, I think I'd find them too boring to drink a two or three $4 glasses at a bar though.

This is a great idea. In addition, consider flavouring to your taste by just mixing with soda.

I had an obsession with sprite/7-up one summer. The diet variety tasted awful and the regular not only was so high in calories, it was too sweet for me. I ended up with a 60/40 mix of club soda/sprite. It gives it a wonderful lightness while maintaining that great fizziness. It became my summer patio reading drink.