We stayed at the BC the first week of May. We had Ps's for Whispering Canyon and Chef Mickey's. We took the bus to Mk and then boated over to the WL and took the monorail to CR. It is time consuming to get from resort to resort unless you have your own car or take a taxi.
I wouldn't be concerned about the mold problem at the Poly. We have never had a moldy room and all the longhouses have just been refurbished. I LOVE the Poly. The BC was nice, Storm Along Bay is great, but the Poly is magical. The transportation options are better from the Poly and if you have little kids and are going to spend more time at MK, the Poly can't be beat.
I love the Deluxe hotels, I have never stayed at a moderate or value so can't comment. The deluxes have queen size beds and the rooms are larger. I know some people don't spend a lot of time in their room, but it is nice when you do. The dinning options are better at Deluxes also. I guess you can say we are deluxe snobs. I think it is the only way to go. I have heard good things about POR and POFQ also.