Carpet area efficiency: The real dealbreaker for me

Under-construction projects give more room for negotiation, I feel. Prestige City ka carpet area efficiency kaisa hai? Keya Life By The Lake toh ready hai, but uska price point kaafi high lag raha. Konse amenities actually use hote hain? Builder trust factor bhi sochna hai. Kya Prestige ka wait karna chahiye ya Keya Life better hai?