When I decided to go back to Plasma after a couple of years in Ubuntu's Unity and later GNOME, my feelings could not have been more positive. It was fast, customizable, and reminded me of what I felt when using Ubuntu pre-Unity, with the main difference being a more careful design. But not everything was perfect: I soon realized that higher productivity was accompanied by higher energy consumption.
Right now I have two laptops with Plasma, but I cannot and will not talk about one of them because the battery is already in the last. In my newer laptop, the battery is relatively good, and better than it will be in the future, as Michael Larabel explains in su Blog. Although in its medium we can read current news, Phoronix stands out for its articles on performance (Benchmarks) and other tests it does on software and hardware. In the last one he has done, he has verified that Plasma last longer without charging in Wayland than in X.Org.
Plasma will move to Wayland, but not in the short term
Larabel stood face to face with the v5.23.5 of Plasma in Wayland and X.Org and compared them with those of GNOME. The most popular graphical environment, partly because it is used in the major versions of Debian, Ubuntu or Fedora, still offers more autonomy, but KDE in Wayland is showing good results.
The bad thing is that Wayland does not perform as well as X.Org, not yet, and that is something that is noticeable in some games. Although some are not so clear (I stay in the middle), Wayland is part of the future of Linux, the present already in GNOME, and will improve even more in the coming months. If that improvement is added to the productivity and customization of Plasma, things are looking good.