Originally Posted by Zorak

GMs can clear anywhere from as early as 3 days (and with recent changes that appears to mean literally ~72 hours, it used to be 5pm the day before) depending on inventory, to not clearing until the gate if DL revenue management holds back inventory because it thinks it can sell more F seats.

EDIT: I think I slightly misread your question. You can try searching the success thread for "PHX" (include the quotation marks or FT will probably reject it as being too short a search term)

http://www.flyertalk.com/forum/delta...k-thereof.html

and the 2016 version:

http://www.flyertalk.com/forum/delta...k-thereof.html

Depending on your travel patterns the best benefits of GM over FO are having Sky Priority, waived SDC fees, and Sky Club access on international itineraries.