I use mine but I lament that it is so small. I would use it a lot more if it were at least 18" wide.

It depends on layout….

Here's the layout of that helps

I have two friends with ’prep’ sinks. One only used theirs as a cooler for wine bottles during parties. The other uses it to collect mail.

You are going to do a lot of your prep in the small area of counterspace between the cooktop and the sink on the perimeter, unless you are rolling out cookies or doing something that takes a lot of space. That's just human nature. Even if you have lots of counterspace somewhere else.

If you have a sink in the island you May do more prep on the island. But I feel like most people do not want to carry stuff back and forth over to the stove, they want to work next to it.

My island sink is my only sink; I'd rather have it where you have yours, but my kitchen doesn't allow that. I would not add a sink (full size or smaller) to an island.

Definitely no sink on island. Too small. But in general, two sinks is way overkill in a kitchen this size. Agree that it may be worth exploring some alternative layouts and being flexible on having a sink under the window as that seems to be driving some suboptimal choices here.

I spend most of my time doing something at the sink. I like it under a window and not on an island with everyone watching the mess unfold lol. Definitely no sink on this island.

one more thought. splurge on a great sink and faucet. something you will love.