I've stayed at both, and loved them both, but no resort quite matches the GF (in my opinion). And for the same price, that's a no brainer.
I almost hate to do it - because I really love the Boardwalk - but I totally agree with this statement.
We've stayed at the Boardwalk 3 times (twice on the Inn side - standard view, once on the Villas side - Boardwalk view). All stays were lovely - we really like the theming and being able to walk to 2 parks.
Then we stayed at the Grand Floridian over Marathon Weekend (January 9-13 this year) using a pretty decent AP rate (we were originally booked at the Poly but no discounts ever came out for that resort during our stay). Let me address the main issues people seem to have brought up with the resort in this thread:
1. Stuffiness of the resort. As excited as I was to stay at the GF I was also a bit nervous...I felt like I was going to walk in and people were immediately going to know that I didn't belong there. But from the moment I stepped of the Magical Express I felt completely welcome and comfortable. The CMs at this resort are so incredibly friendly - from the guy that checked me in to the one that offered me a ride back to my room to the one that brought my luggage, everyone was fantastic. Start to finish. It made me realize that I'd always assumed the resort would be "stuffy" simply because that's what I'd read everywhere - here, in guidebooks, etc. Once I was actually there I didn't find it to be stuff at all.
2. Construction. Yes, the construction is ugly, but the noise never bothered us...not sure what else to say about it.
Bottom line, if you can get the BW or the GF for the same price...go for the Grand. Or maybe you could do a split stay?