I just feel that over the years, CX Premium Y has been watered down.

I first flew PEY in 2013 longhaul and clearly remember that on short segments like to MNL and TPE combined with the longhaul segments, there was a noticeable price "discount" when one or both short segments were on Y and not PEY. (i.e., LAX-HKG-MNL all in PEY cost more than when one or both of the HKG-MNL segments were in regular Y). I noticed that there were more combinations of PEY codes. For example, you could be traveling outbound in E booking class for PEY, then R class PEY on the return. I guess in part, those explained the price differences.

At that time, whenever there was an aircraft substitution, an agent would call to inform me that I was given a courtesy business upgrade (with the corresponding upgrade in business class booking code and mileage/ club sectors earned).

By 2015, I noticed that all tickets are sold at the same price (except for the upgradeable fares), regardless of whether one segment was in Y. And there is now the tendency that both the outbound and return are on the same booking class codes. Further, they now tend to downgrade you rather than upgrade when you just let them decide.