I've stayed at BLT, VWL, BCV, and BWV.
There's a lot to like about the Epcot area. It's easier to get between all the resorts (and restaurants!) in the area, and Epcot becomes a viable "let's just go in and get dinner" option as well. As a bonus, they are all connected by walking routes that don't go anywhere near traffic, so it's just one continuous resort area. (That's not true of DS, IIRC, but I only walked there a handful of times.)
In contrast, you have to monorail or boat between the MK area resorts (boat only, in the case of WL), and that's cool, but somehow it make them feel ou can walk between Poly and GF, but I've never done it, so can't comment on how that "feels."
Now, if the castle and only the castle is "magic," then I can imagine it would be a little disappointing. But I'm a pretty equal-opportunity guy when it comes to finding cool vacation moments around the WDW area.
Personally, my very favorite of those four is VWL. I love the theme of the resort. I really love the way it feels like it is completely somewhere else, even though MK is just around the corner. I can make do with the less-accessible restaurant landscape in exchange for the overall vibe of VWL.
But, if you are just talking about area (rather than specific resort) I'd choose EP-area over MK-area.