Recently, I had the opportunity to sit next to a retired DL (PMDL) flight attendant. During the course of our in-flight chat (both as non-revs) she pointed out a perceived difference (in her own opinion) between the customer service provided by pre-merger NW and DL customer service/in-flight. Her opinion was that PMDL staff (in flight as well as stations that are/were predominantly pre-merger Delta) seemed to exude a more positive focus on customer service than PMNW stations (I.E. PMNW employees riding the "bitter bus" for one reason or another). I'm curious if any frequent flyers (both pre- and post- merger) have an opinion on this topic? This lady had been flying for DL for 33 years prior to a medically necessary retirement before the merger. I could completely understand she may have a bias in favor of PMDL stations/staff. I recently returned from a non-rev trip to Europe on a PMNW Airbus A330 with a crew I would have to believe was predominantly PMNW and had an excellent in-flight experience (aircraft appearance and service). It makes me wonder if her opinion was isolated or if DL frequent travelers notice a difference.