I like the food at both places, but the Wave is louder and kind of crazy in my experience, on several occasions there seems to be a lot more kids. Kids crawling all over everything, the booth next to me kicking, under tables crawling around. GFC is more relaxing to me, the restaurant is not as loud, the crowd is generally more adults, or better behaved children. I know this is completely subjective, and maybe this isn't the norm, but it has always been like this when we go to the Wave. Often times we've eaten appetizers and had drinks at the Wave Lounge since it isn't as crazy as the main dining room. It is probably more dependent on what time of day you are eating, I'm not sure.
I usually order soup, salad, and fish tacos at the Wave.
I usually order some chicken entrée at GFC, sometimes shrimp appetizer.
At GFC we usually have a later reservation, after 8:30 usually, and the restaurant has been very nice.