We have stayed at WL, BC, and YC after staying at both values and mods. I love them. I love WL where everything is under one roof, so you see the theming every time you go downstairs to get to the restaurant or bus stop. The theming is beautiful, and there is a boat to MK. I love walking to Epcot in five minutes from BC and YC, though I think the theming is a little lacking compared to WL. I haven't walked to DHS from there yet, but I could! Stormalong Bay is amazing. I have not stayed at the monorail resorts yet, and am not sure if I ever will since DH is not too keen on the theming of those resorts and the monorail is not a huge deal since we drive anyway.
I have one issue with both the Poly and GF - and that is that they are in several different buildings and you have to walk outside to get to dining and shopping. Call me spoiled - I love having everything under one roof like WL and BC/YC. I know the buildings are close together at the Poly and GF, like POFQ, but it still dosen't seem right to spend premium money for a resort where you have to travel between buildings and may therefore rarely see the incredible lobby.