I’ve owned one since 1987, but rarely use it today.
I was impressed by the fact that it has lengthy, comprehensive book introductions; chapter sub-headings; tons of footnotes with archeological, historical, geograpgical, linguistic, sociological, theological material; extensive cross-references; maps; index of theological topics, names, places.
What annoyed me were its innovative, non-traditional renderings of many familiar passages, its less-than-conservative stance in its intros and footnotes, and its “mild” inclusive language. I say “mild” because it doesn’t go the lengths of the RNAB or NRSV with use of IL for references to Divine Persons of the Trinity. IMHO, this would’ve been a better choice for an IL lectionary than either the RNAB or NRSV.
Disclaimer: I’m only stating my preference for the NJB when the choices are the NJB, the RNAB, or the NRSV.