The hotel either absorbs the distance or it doubles it. Sultanahmet absorbs it for a proper city layover. An airport hotel absorbs it when the clock does not.
At Istanbul Airport
The honest choice when you land after mid-afternoon and fly the next morning, or whenever the thought of a 90 minute return makes you tired.
You can still go into Sultanahmet for a late afternoon if you arrive early and come straight back. The room is what makes that safe.
A good 48 or 72 hour base if you care more about food and the Galata side than about rolling out of bed into a mosque courtyard. It adds a transfer on the monument day.
It is the wrong call for a tight 24 hour layover. Stay up the hill in Sultanahmet and visit Galata on a longer gap.