Hi everyone. We actually did the BCV (studio) first and then went to the Poly. Originally I had the Poly booked for the beginning of the trip and then the BCV because DS and DH LOVE SAB at the BC, but DH's vacation changed so I just kept our reservation at the Poly and put the BCV 6 days before.
Missus Toad: If I had a choice to redo it yes, I would have done the Poly first and then BCV because DS thought the Poly slide was not as nice as the one at SAB. There also seemed to be more teenagers(he is 14) around SAB then at the Poly when we were there so DS said he enjoyed the first part of the vacation better. However, I see your children are young so I think you will truly enjoy the shorter stay at the BCV first and then the longer one at the Poly with the smaller main pool (easier to watch and take care of the little ones) and having the convenience of the monorail for the MK!
Maxiesmom: While I agree with my DS that the BCVs are beautiful, I personally enjoyed the Poly. I have not been there in over 10 years and the room renovations were very nice. I liked the volcano pool at the Poly and watching the fireworks from the pool at night was very special.
DBFLUKE: I think you will love the Poly. We stayed at Rarotonga, which was right next to the Ceremonial House which was very convenient. We were just a few doors down from the elevator on the 2nd floor. We did not have a balcony but it really was too hot to sit on the balcony. Personally, since it was 94-97 degrees while we were there, I was very happy to be close to the Ceremonial House. Your request for Samoa is good in that it also is close to the Ceremonial House and very close to the pools. I did not really notice Tahiti while there but I hear that one has great views of the MK so you can not go wrong either way.
It really is a beautiful resort!! The Volcano pool(the main pool) was open until midnight and the slide open until 10pm. The latest we stayed at the other pool was 11:00ish but I have a feeling that you could go there even after 12am since there are never life guards at that pool. I am sorry we have never eaten at Whispering Canyon so I really do not know the best way to get there, but I would say your plan of going to the MK first and then a boat to WC sounds like a good plan to me. Just alow yourself about 1 hour to travel. We had a rental car so we actually never took any of the buses, just walked to Epcot from the BCV or took the monorail or boats to the Poly. The monorail was wonderful and very quick!!
I wish all of you wonderful trips!! Both resorts are beautiful in their own way IMHO. Have fun!! Any more questions, just ask.