Sometimes these types of topics get repetitive, but sometimes they offer real gems.
But the biggest takeaway for me is everyone has their likes/dislikes/needs/wants so having a choice between different WMs/DEs is good. Some want least resource usage, others want a lot of flash and sparkly things. Neither is wrong, it just "is".
My opinion:
Gershwin: to me the NexTstep interface is one of the most elegant/cohesive environments I've used/seen. Bringing that to OpenSource is huge. Not everyone is going to like it, but hey, there are choices.
KDE/Gnome: for me, bloated for what they offer, but I can understand the appeal. They can give you consistency of how things work.
It all boils down to what you want/need. I like a simple window manager, not a full blown desktop environment. Been using Windowmaker for a long time (maybe 20 years?), played with others (awesome, fvwm, openbox, twm) but usually circle back. I'm currently testdriving JWM; so far it's good.
Bottom line:
Sometimes we see these threads and go "Really? Again? Yet Another Topic About Window Managers?" (YATAWM) but the responses always change and offer me an opportunity to reevaluate what I'm using.