We've tried 3 CL's.....GF (both RPC and SL) and WL. I would rank them:
1. GF RPC - spacious lounge, great offerings, wonderful CMs, pretty views from the lounge.
2. WL CL - the lounge has plenty of seating that is arranged around the railing overlooking the lobby, food offerings are great, CMs are very friendly and accommodating
3. GF SL - didn't care for this CL as the lounge is small (IMO) and does not have enough seating to accommodate the number of people that stay there, the location of the lounge is right inside the lobby of the SL building which (to me) made it very chaotic
We have stayed at Poly and BC CL. Poly wins, hands down. So much space, and the view of the MK fireworks, with music piped in! BC was nice, but very cramped.