I have read posts about application windows darkening, freezing temporarily
and it happens in my case, too, especially when I have many resiurce-hungry
applications running, with large files etc. I have also read about complaints of
Firefox starting too slow in gnome or Gnome being slow.
I experimented with many desktop environments and window managers and I can
say many of them are, in fact, very user-friendly. For somebody who wants speed,
comfort and usability I think XFCE is the best choice.
It is snappy, fast, folders open quickly, applications start very fast and
application windows do not blacken.
There is however one problem that I have in XFCE: I cannot get the sound to
work. In everything else it works.