After having switched to KDE from Gnome, I can say Gnome Shell does hurt productivity. One example would be, Nautilus can't be split into two panes. When I have to move a bunch of files from one folder to another, on Gnome it would require right-click copy and then open the folder and then right-click-paste. Whereas on KDE, it merely means drag and drop. It will even ask you, if you want to move or copy, that could come handy at times. Usually, I have a working folder open in split and a new tab if I want a full folder.
Secondly, KDE comes with a full suite of applications [1] that all follow same philosophy of user choice than minimalism. Gnome severely lacks that kind of application database. For example, there are not many applications, including big names like Banshee, that use Gnome's message tray. Some applications use split menu and some don't. Overall, it's not a great user experience. Not to mention there is no way in Gnome to entertain Dropbox icon which is specifically designed for system tray.
And you could say that file managers hurt productivity because they need you to focus on the file, after finding the specific one you were going to move. And then you have to wait for it to ask and focus your view on the option you were to choose, when you had the option to go with mv or cp in the first place and you don't have to navigate to the folder you need to copy the files either.
You get split Nautilus windows in GNOME the same way you get split anything windows: tile the window to the left (Super+Left or drag window until mouse touches the left screen edge), open new Nautilus window, tile it to the right (Super+Right or draw window until mouse touches the right screen edge). Presto.
For moving and copying files from one directory to another, it's arguable that Gnome's select files, right-click and select "Move To", or "Copy To" from the context menu and select the destination from the resulting dialog is as efficient as the split-pane way.
Secondly, KDE comes with a full suite of applications [1] that all follow same philosophy of user choice than minimalism. Gnome severely lacks that kind of application database. For example, there are not many applications, including big names like Banshee, that use Gnome's message tray. Some applications use split menu and some don't. Overall, it's not a great user experience. Not to mention there is no way in Gnome to entertain Dropbox icon which is specifically designed for system tray.
[1] http://www.kde.org/applications/