I was looking at general curve labels, and not thinking about alignments.
Alignment Labels generally, have been invaluable to me lately; I can even 'grade' an entire site (lots, finished floors, etc) using nothing but an Alignment + Profile + Station Offset Labels w/Expressions.
That said, the only 'gotcha' I've found to-date, is when labeling Profile data in plan view via Alignment Labels - specifically a symmetrical Vertical Curve's PVI + High Point, as example - they list the same Elevation, even though the Crest info (in Profile View) correctly shows them as being different.
Cheers