Yes, it's worth it. This has been discussed in another thread quite recently and that included a list of PP lounges in the USA. The only caveat is that your post implies you do most of your flying on Delta. DL excluded most of the Crown Rooms at its major hubs from the PP scheme e.g. there is nothing at CVG or SLC, only councourse E at ATL, etc.

See http://www.flyertalk.com/forum/Forum94/HTML/000739.html

[This message has been edited by james (edited 03-24-2000).]