1. UA's main competition are the other U.S. legacy carriers (DL, UA).
2. UA is virtually all lie flat (3 777s to go).
3. AA is almost no lie flat
4. DL is less than halfway through their conversion.
5. Don't know what the AA product will be but compared to DL.
Privacy - DL wins
Direct Aisle Access - DL wins
Storage Space - DL wins
Seat Comfort/Size - UA wins
I'm amazed that the UA product despite being very old is (IMHO) still better than their main competition in terms of comfort. The DL (and other products) look slick, but for me getting a good sleep is the most important criteria when I'm picking flights for a long trip.