I'm surprised by the reviews I've read for Thai Island, because I was impressed with it. It's fast food Thai and it's quite yummy with fresh ingredients and the service is fast. I don't know what else more you could ask of a take away Thai business? The reviews for the various locations all say "I could get way better for the same price at a sit-down restaurant." - but you're not at a sit down restaurant. You're eating take-away, so judge the place by take-away standards. The food gets prepped quite differently in order to be ready in 5 minutes or less. It's a different ballgame.
With that said I enjoy the food here. Yes, it's not sit-down restaurant quality, but I don't go to McDonalds and get angry it's not Burger Shack.