So a while ago in one of the other sub-forums, someone asked about what features people really want to see return to the pokemon franchise, one of my answers was that I wanted to see "Berry Pots" return from HG/SS.
With the introduction of Pokepelago, it was like my wish was granted and also upgraded with the significantly larger amount of berries that could be grown simultaneously. I also really enjoy the other additions to the Pokepelago.
I will admit that the Bean producing isle has quickly become not as useful since I now have all the isles upgraded, and the closeness and fullness meters generally rise faster than my ability to spend my beans on my pokemon, I have about 200 of every kind of bean at the moment, but still the bean collecting was an awesome mechanic while I was playing the main story line of the game.
The treasure collecting Isle is amazing, I think it's also a smart mechanic they added to the game to encourage players to keep returning to the game day after day. I guess this is sort of true for all of the Pokepelago isles, since they all refresh or have expiring timers after approximately a day. It basically shows that in order to get the most out of these games, you have to regularly return to playing the game each day in order to collect your various resources in order to make further progress within the game such as collecting items from the treasure isle to make more money or to find hard to acquire items.
The training Isle is awesome as well, it provides a means of EV training a maximum of up to three parties of pokemon which isn't even counting the fact that on top of those three parties on the isle, you could simultaneously be training a fourth party by just playing the game naturally. This is truly a god send, since it does 3x the EV training of the previous games, it also takes out the tedium of individually training each pokemon's EV's in Super Training. Competitive players rejoice!
Last but not Least, the Spa Isle, this isle is easily one of the most amazing ones to me due to my obsession with breeding. Three parties of eggs can just sit in my box until they hatch while I'm busy working on my own party filled with eggs. I can hatch 23 eggs in almost about the same amount of time it used to take me to hatch 5 eggs in OR. That is such an insanely impressive upgrade from before, and it has begun to spoil me as a breeder making it all that much harder to go back to breeding in the previous generation.
All in all, I have really been enjoying the Pokepelago and I feel like it has been spoiling me silly, even on days when I don't have time to really get any actual game play time in, I always have a little bit of time each day to quickly check my Pokepelago and reap all of the benefits that it yields.