To put it lightly, I've stayed in the Polynesian on several occassions, and at the GF once, and the CBR still holds my heart, even though I stayed there after staying at the GF and Poly.
To me the ambiance of the Caribbean atmosphere will always be better than the induced artificiality of the GF. It's more laid back, more sunny because your door opens right outside, and what could be better than walking to the food court OUTSIDE at a moderate, rather than through stuffy (though very nicely decorated) hallways INSIDE a deluxe?
To me Disney is about being outside, yet relaxing and having fun. I LOVE the moderates, all 3 that I have stayed at, at least, and the only reason we are trying out a deluxe for half of our honeymoon is because DH and I are insane animal lovers!

(AKA The AKL is where well be after our stay at the CBR).
Moderates are wonderful, they have many ammenities that a deluxe has, like watercraft rentals, jogging paths, game rooms, AND they have something deluxes lack.
A REAL FOOD COURT!
I'm sorry, but Deluxe food courts are not very good. At least not in comparison to the moderate and value food courts, and I like to get up and GO when at WDW, and the moderate food courts allow me to do that, with a better selection, a lot quicker than the deluxe food courts would (because they have more limited selections).
So do you want to be able to go everywhere quickly in the morning, with a nice selection of food, AND save money? Then go with a Moderate! You can always go to restaurants for sit down meals at other resorts if that is important to you.
ALSO, think of ALL the fun activities you will have money to do now, if you save money by staying moderate.
Aqua Seas Tours, Surfing at Typhoon Lagoon, Dolphins in Depth, possibly Discovery Cove....
To me the chance to do more of those is by far worht the money saved from staying at a moderate. Plus, extra souvenir money! Have a good one!