Not intended to be a direct reply to Pat.
We usually tip 20% plus or minus on the Dutch side, and minus any listed service charge or any other extra charges the place adds to the check. Not an issue for us and we pay attention to this better than we used to. I think it would be better if they did 15 to 18% but really doesn't change our decision to go there or not. From the sounds of it they clearly state it on the check and don't try to tell you that it isn't a tip or service charge. I just don't see a problem with this considering how many nationalities frequent the island and how different tipping is done across the world.
We will be visiting this place when on island, looking forward to trying it.
T