I find loop labels quite useful for comprehension, particularly for next/last calls if the loop gets long or nested (although both indicate some other refactoring is probably needed). The example provided by tobyink in 11115607 sums it up nicely.

The laufeyjarson blog series on PBP might also be of general interest. Loop labels are covered in http://blog.laufeyjarson.com/2015/02/pbp-084-loop-labels/.