I have Linux on all my servers, was an early (very minor) dev on pre-1 kernel and generally love it.
The desktop is a walking nightmare. Something continuously does not work: multiple screens, waking up from sleep etc.
I really would like to move (we use Outlook but I am even ready to go for OWA) but Windows is considerably better on laptops.
Again, I love Linux and have managed literally thousands of them since 1994.
Part of it is the laptops are developed for windows ACPI interpreter, for windows wifi drivers, for windows system level hack drivers etc. It takes time for Linux to figure out individual workarounds. At least for XPS Dell seem to be developing also for it to work on Linux.