Very different, I think...I have a birthday coming up. I am considering both of these restaurants. I know that Proof is very "in" and in a fun part of town. The food has gotten really good reviews too. Bistro Bis is probably more staid but I love Vidalia and they have the same owners. My concern is that Bistro Bis might be dead on a Saturday because it mostly serves the Hill. We don't want dinner in too quiet an atmosphere. Also, has the food remained consistent over the years? Please advise. Thanks.