[cptskippy]

You're right that it's opt-out with Microsoft and opt-in with Apple. However Microsoft's opt-out screen appears during setup before you ever even reach the desktop. Where as Apple's opt-in is a nag that occurs periodically as you use the device or anytime you install an update.

I understand that Apple has publicly disclosed how they anonymize data and roll identifiers but Microsoft hasn't so you really can't say if telemetry data can be tied back to a user or not because you don't know.

[dkonofalski]

Apple's opt-in is only triggered when you attempt to use a feature that relies on a function of the opt-in or when a new OS feature utilizes those functions. It's not a nag. It doesn't ask you until you want to use it. Microsoft assumes you want to use it and hides the opt-out settings under an "Advanced" button during setup when it asks about new features and then promptly asks you again after it assumes that you don't know what you're doing. The "Are you sure?" prompts on Windows are far more egregious.

[addicted]

But that's basically spotlight so it's a difference with little meaning IMO.