I’m assuming you’re asking about the resorts themselves, since booking was already covered
We own at Poly & have often visited the idea of owning at WL… so, I understand the draw for both.

They are very different!! First off- at CCV (nearly) everything is under one roof (lobby, restaurants, gift shop, your room, laundry room, walkway to/& inc the bus stop); while at Poly things are more spread out with no covered walkways (main house inc lobby, restaurants, gift shop & monorail platform… longhouses contain your rooms & the laundry room might be in a different longhouse!). Both resorts have very good dining options, but they are quite different from one another… I personally give the edge to the WL.
The rooms themselves are wildly different from each other too!! CCV studios are among the smallest
DVC rooms (with a small bathroom with 1 sink), while Poly’s are among the largest (with a huge “split bath” inc two showers & 2 sinks). However, unless we dive into cabin vs bungalow… there are no other categories to compare- if you buy into Poly (as it currently stands), you need to like staying in studios.
Both resorts have nice quiet pools, and the feature pools are fun.

Poly has a beach, and WL has nice lagoon-view outdoor seating… fantastic spots to chill. WL definitely has the Lodge vibe going for it, and Poly has a fun Tiki vibe. Both are fantastic!! Poly has much better fireworks viewing, and -of course- there’s dole whip
