I'd prefer more land. Though the water one is cool, I feel like it would really limit what you could do and make it feel choppy. But I do wonder if they will have a cap on the percentage of water you can put on your island.

In this picture (compliments to emkeystaar on reddit) the island is more land based with the standard river or two.
View attachment 231993
Then here (u/thezemekis) is a island that is covered in mote features.
View attachment 231994