As with most things in life... it depends. And look, it goes both ways. We could cast aspersions on RW goers and color them cheap, lousy-tipping amateurs.
The restaurant should offer the entire menu. No choose from two or three options in each category. The serving size should not vary and the crew needs to be up to the task of handling the crowds with a smile.
Up charging is offensiive - either offer or don't. Don't lure me in at 35 bucks and change only to pad my bill if I choose something in particular.
The diners need to reward the server with a kind tip-think about what the meal usually costs and tip based on that - not the discount.
When both parties act in the true spirit of RW, everyone wins.
Incidentally, I did partake in RW in DC this week, and had a lovely experience.