Once upon a time Spoodles was one of our favorite restaurants at WDW, since then it has taken that ill-fated "gone downhill" plunge that some of the other WDW restaurants have taken, the service has also taken that same downhill plunge.
While we do still enjoy their breakfast we've tried to enjoy our dinners there a few times in the past few years but it's just not what it once was. That being said, if you have nothing to compare it to, you might like it. The menu is very limited now so make sure you check it out before making an ADR.
On the other hand, FF is on our current "favorite" list. Food is excellent, service is up to par. This has been consistent for the past 2 years that we've been dining here on a regular basis. The seafood is always fresh, I just love their mussels! DD loves this place as well and has been eating here since she was 5.
But, of course, it also depends on your budget as already mentioned, FF is definitely in the higher end category--but it is still very "kid-friendly". Spoodles is not cheap but is definitely less expensive. Personally for the quality of the food and service in comparison I'd splurge on the extra and go for FF, but that's me. Both menus offer similar kids items, so you shouldn't have a problem with your picky 6 yr old dd, mine was also picky however this is where she started eating salad and ranch dressing right about that age!
