Users of the popular linux-centric desktop environment known as KDE were presented a choice a few months ago. They could either adopt the new KDE 4.0, or remain on the KDE 3.5. The choice probably wasn't easy. Users that decided to keep the old were no longer going to be the recipients of new features and upgrades, or at least not the primary focus any longer. Users that wanted to upgrade had to be willing to give up a lot of functionality that they were used to.
I made the choice to upgrade, following the philosophy that new is typically better. It wasn't until I gave up some of the old functionality and was discussing with a friend that I even knew some things existed.
It has been a few months now, and recently I have upgraded to the 4.2 version of KDE. The visual components of KDE have been stellar in regard to appearance ever since I originally switched, and I have steadily been receiving functional improvements that make it usable as a desktop environment. I am still having some issues, such as plasmids being ridiculously slow, occasionally my mouse will disconnect from my screen, or Akonadai will not startup. Despite these issues, I'm really enjoying the 4.X version of KDE, participating as an explorer of the new frontier of desktop computing.