I too agree with JRF, there should be a level above PM for those of us who fly 150k +/year. I know I would bring more business to DL, especially now, 6 PMU's for 100k, or 200k, or 300k, no real benefit for flying more than 100k/year, except accumulation of miles and NAMU's.
Additional benefits could be the re-introduction of SWU, upgrades on lowest fares, CRC for spouse/companion, easire availability of upgrades, no $100.00 change/reissue fee.
Wishful thinking...