I have played this game since launch and have multiple max level characters and have most of the achievements on my main character and have done a lot of content in general. One thing I have noticed lately is the reduction in usable rewards per amount of time spent in the game. I get that ZOS loves to put a lottery behind every piece of equipment and in some cases it can make finally getting that fifth piece of awesome armor special, but lately I feel like the game is more frustrating than rewarding.
For example, I would really like to have Spell Power Cure on my Nightblade, and have been running Vet. White Gold Tower ad-nauseam to get it. I have almost all of the achievements on 2 toons (DPS and Tank) and just got the "no-death" achievement on my tank yesterday. It takes about 5 runs to get enough trophies to turn in one trophy key for a chance at 2 set pieces, and it seems that my drop rate for the dungeon itself is about 1 piece of Spell Power Cure per 10 runs. For all of my efforts and the keys I have turned in I have been rewarded with 3 pieces of armor and only one of which is a desirable trait. Ironically I now have 4 Molag Kena heads, so the drop rate is actually slightly better for those...
At this rate I will probably have a Molag Kena head for each of my 8 toons before I get 5 pieces of Spell Power Cure with good traits.

All kidding aside, this is not the first time I or another player has experienced this level of frustration with the RNG in this game. A friend of mine got his last piece of Infallible Aether just in time for it to get nerfed, then made obsolete by V16. I figure the same will happen to me... I will get my 5 pieces just in time for VR18, or CP180, or whatever the next iteration is.
I like the idea of getting trophies so that at least after ~5 runs I can have 2 set pieces of something, but so far only one of those has yielded what I actually wanted. I would like to appeal to ZOS to really take a look at this and try to think of a way to make this less frustrating.
For example, I really like what they did with the Tel-Var system where you could directly buy a piece of armor with Impenetrable trait, or try your luck with the bags for a chance of a better trait. If they did the same here with a vendor inside the vault that you could spend your trophies with at least then I wouldn't feel so unrewarded. I could run around with impenetrable spell power cure until the RNG gods smiled on me and gave me something better.
Another option would be to have a chest for each armor type, so at least I could open a light armor chest and get a chance of Overwelming or Spell Power Cure, and the tank I was running with that really wanted the Imperium set, but was getting the Spell Power Cure wouldn't feel so unrewarded too.
Anyway, I will continue to play the game and pay a subscription as long as it is still fun, but this is a mark in the "not fun" category in my book.
Playing since beta...