Ko Yao

My husband and I are planing a trip to Ko Yao in November and we have a couple questions we hope someone out there might be able to answer. Which of the two islands would you recommend - Yai or Noi? Are there big differences between them? We have read that Noi is more developped than Yai, but that Noi is supposed to be the more beautiful island? We wish to go somewhere where there aren´t a lot of tourists but that has a small selection of places to eat. We would also be happy if someone could give us recommendations on accomodation (max 4000 BTH/night) on the beach and with airconditioning.

Thank you!