You can't go wrong with either one---they both have their own charm.
I must say though---BWI for F&W can't be beat and it's more compact than POR. POR is a large spread-out resort. Some rooms are quite a hike from the food court and bus stops. Just depends on your bldg location.
With BWI, I like having a 1) balcony 2) ability to walk in and around the BWI/BWV in inclement weather 3)easy walk to Epcot and boat ride to DHS. Just my preference for BWI---I like POR and think it's a beautiful resort and makes the budget not feel the pinch as much. But you will give up some nice perks I feel. As long as you are aware of them and are ok, it's not a problem.
Also, I feel there is more to do for non-park entertainment around the boardwalk area like Jelly Rolls and ADH. I know we have done F&W the past 3 years and go back multiple days so we can visit each and every booth and take in all the event has to offer. Being able to walk back to your room is invaluable. But if you only plan on a day or two at F&W, a split stay would be fine too. I'm sure whatever your choice you'll have a great time