"Pleasant" is too general for my taste. Dict.cc gives the words "comfortable" and "cozy", which are better translations in my opinion.
Note also that "Gemütlichkeit" not only describes an atmosphere but also a state of mind, something like "laziness" but not so strong.
By using the word for your work place, you essentially say that you have (and use) the possibility to work less hard and slower than you could. So you better make sure your boss is out of earshot, because otherwise, he will certainly take measures to make your work less "gemütlich".
Maybe you know Disney's Jungle Book and the scene/song in which Baloo shows Mowgli his way of living. In the German version the chorus starts with "Probier's mal mit Gemütlichkeit". I think Baloo's life style is a good example of "Gemütlichkeit".