We currently live on an island, not in Scotland.
Personally I hate it, the weather is awful, you really need to be a "no bad weather, just bad clothing" person. There's a pervasive dampness that rolls off the sea that leads to a lot of windy grey days for a lot of the year. When it's sunshining it's beautiful, but there aren't a lot of sunny days.
The ferries are expensive as you need to put your car on, also in winter there are frequent cancellations. If you have family on the mainland, kids at uni etc then it can be hard to get back in an emergency and it's a horrible feeling knowing you are needed, but you can't just jump in the car and go.
We have a hospital, better than many islands, but more serious things mean being helicoptered to the mainland. If you have a heart attack in bad weather you will have to wait. You have to travel for some cancer treatments.
Our kids had to give up certain sports when they moved here, which didn't go down well. Also support for SEN is poor. Friendship pool can be small and incomers are transient.
You'll always be a incomer. Always.
Getting things delivered can be a right pain in the arse and expensive.
I wouldn't recommend. But each to their own. There's also the risk that one of you might hate it and one might really settle, which I have seen happen a few times.
On the plus side it's safe, kids have a lot of freedom, but there are issues with alcohol, drugs and higher suicide rates although I think that can be the case in many rural communities.