We expanding GNOME at our office at the expense
of mostly Windows 95. While GNOME, Fedora, OpenOffice.org, Firefox,
etc. are excellent tools, they could use some polish in certain areas.
Also, some of the following aren't GNOME or KDE's fault.
GNOME and KDE need better configuration management. Sabayon is very
immature (e.g. it got confused by a URL in a value and though the URL
was a comment because it had //). Kiosktool could use a lot of help
too. Then, many programs (xscreensaver, OpenOffice.org, XMMS) simply
aren't managed by Sabayon or Kiosktool. OpenOffice.org's XML registry
is relatively difficult to manage using the command line: you can't use
sed with OOo, for example, like with XMMS.
KDE's printing system is great, and GNOME's is OK. But not many
programs use these print systems. For example, it's a difficult to make
Firefox use non-default printing options such as trays and duplex.
Also, Evince's printing is horribly broken, and Adobe Acrobat Reader
doesn't know CUPS exists.
People just don't get the GTK file chooser: it's confusing. Novices end
up saving everything into one directory as the default file type. And
for me, it's really annoying to expand the options for browsing for
files and file types, and then it's cumbersome to navigate the
directory tree with the keyboard. On the other hand, the KDE file
chooser is excellent.
Nautilus and Konqueror should have built-in tools for manipulating POSIX and NT ACL file permissions.
Otherwise, we use GNOME at our office, and I really like it.