Originally Posted by
akonradi
KVS doesn't show upgrade availability for Delta. It will never display V, G, X or Z inventories, even if space exists.
That is correct, ExpertFlyer.com is the only way to see the DL upgrade inventory class values.
Originally Posted by
traveller99
It is for me. My wife and I are both PM and we typically choose SWU for perks. We fly TPAC and TATL twice a year and use EF to search for Z availability before we buy the tickets. Always the best way to go.

Glad we're able to help out
traveller99!