STID has plenty of dark grit compared to the previous films.
Was it the lack of comic relief in SKYFALL that put you off?
That may the biggest difference between the two movies.
Despite the title, I didn't find the overall tone of STiD
excessively dark at all. Yes, there was death and sorrow, but there was also color and humor and energy. There was friendship, love, camaraderie, and casual sex with twin catgirls. There were heroes tempted to hatred and vengeance (those favorite Hollywood character motivations) who found their better instincts. There were actors who brought spirit and wit to their performances, instead of mistaking unrelieved dourness for artistry.
Basically, it was a movie that left me feeling exhilarated and buoyant -- feelings I have sadly resigned myself to never taking away from a CraigBond film.