I followed this closely over the years with EVA which started offering premium economy (called Economy Deluxe (ED) then renamed to Evergreen Deluxe then renamed to Elite) since 1992.

They were initially very ambitious. The original plan was the 2/3 of the lower deck of the 744 had ED (F/C upstairs). They quickly realized it was not getting enough people and changed it to 1/3 of the 744 cabin.

Over the years, they tinkered with it - like having dedicated check-in counter and bag tag. ED classes also awarded more miles and required more miles to redeem.

When they went to the current generation on the 77W, they renamed it to Eltie and drastically shrank the cabin. The fare differential also went up over the years - initially, it was about US$200 more for LAX-TPE R/T but I heard now it is in the $400+ range. So, a lot of people are getting priced out/don't think it is worth the difference anymore. It also shows there is the demand for them to keep increasing the fare differential.

The interesting is when they join *A in 2.5 weeks, the "Y" booking code books into regular economy. The cabin also does not appear accessible for *A award redemption.

So, I thiink it would take years to grow a product like this and it also creates some interesting logistic issues. If done right, it is something that distinguishes an airline and attracts passengers. I just don't think UA can or want to undertake a true premium economy class at this time. So, E+ is really what we will have - maybe just a little more perks but nothing more...