The resort is very close to International Airport, only 5 mins by transporation you can arrive there, so that you do not need to worry about missing your return flight unless you oversleep. It is also located in convenient area, city centre can be accessed within 5 mins as well by taxi. You can book in Resort's Concierge and ask for the fixed price, it's around RM $10 - $12.
We took food and drinks in different restaurants - Italian, Aussie Grill, seafood, Local food. Prices are really reasonable and not expensive. If you like shopping, KK is not really shopping paradise since most of famous branded products cannot be found there.
What you need to prepare in advance is a map and you can circle out the places you like to visit, so that you will not waste your valuable time.
The resort is full of sport facilites - Golf, tennis, swimming pool, yacht club.. etc. You can visit the website for your reference:
http://www.magellansutera-kotakinabalu.com/accommodations.php
Spa is also not expensive and you must try for at least once. All employees are with certificates and trained by Balinese, they will offer you professional advices if you have queries on muscluar problem. I was lucky that 40% early bird discount was offered. I could enjoy it around RM$150 (tax inclusive).
My advice is ready for your own holidays, book flight ticket and resort. You must go there at least once.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC