My take is: if the code is type-agnostic (i.e. should remain identical when the type changes), and writing the type wouldn't help the reader, and the type itself isn't already a simple-to-write template (like T), then use auto. (For example, this is the case when you're just taking some value and passing it along, and have no reason to care about the type at all.) Otherwise, write it out.
The intent being that you should prefer to spell out the type unless it's genuinely adding a burden (such as being difficult to read, or adding an extra location to update if it ever changes) when the benefits are also negligible, because it's frequently useful information and a good sanity check.
My take is: if the code is type-agnostic (i.e. should remain identical when the type changes), and writing the type wouldn't help the reader, and the type itself isn't already a simple-to-write template (like T), then use auto. (For example, this is the case when you're just taking some value and passing it along, and have no reason to care about the type at all.) Otherwise, write it out.
The intent being that you should prefer to spell out the type unless it's genuinely adding a burden (such as being difficult to read, or adding an extra location to update if it ever changes) when the benefits are also negligible, because it's frequently useful information and a good sanity check.