We have a legacy application that has a sizeable group of power users. We will be releasing a new feature that will improve the experience for new and regular users, but we know it will impact the workflow for power users on a specific page and will likely irritate them.
How many details should the new feature popover cover? Should information about what power users need to tweak in their workflow be a part of this message? Or is it sufficient to simply notify users that there's a new feature and have them figure it out?
Note: power users in this case are not particularly computer savvy people. They simply happen to use our system a lot and have gotten used to the old, somewhat quirky, system.