I'll take a stab at convincing you
The Poly is in my top 2 favorite resorts(GF is the other). The atmosphere creates an island vacation while on a Disney vacation. It is so magical to hang out at the lava pool or on the beach and listen to the sounds of the ferry boats and the train at MK while gazing over the lagoon at the castle all while sipping on a Pina Colava. At night, the tiki torches and the sounds of the music from the luau make this resort just intoxicating. Grab a Dole whip and stroll on over to one of the beaches and watch the EWP and the fireworks show over the changing colors of the castle.
If that isn't enough, there is a walking path over to the GF which is a lovely serene diversion whether for pleasure or to catch a bite to eat. Speaking of eating, not only does Poly have great QS and TS, being on the monorail and a boat ride away from GF, CR, WL and FW, it has a multitude of EASY eating options without ever stepping on a bus.
The rooms are more spacious than BC/YC and have really great storage. Having smaller outer buildings instead of one large building means quiet rooms with less indoor foot traffic and beautiful foliage to explore while traversing the resort for amenities.
All of this without even mentioning the great transportation to MK via boats or monorail.....
While BC/YC is a beautiful area, it just doesn't have the same atmosphere being on seven seas lagoon across from MK that is really just magical. You will LOVE staying at the Poly. Hope that helps