I still play, I bought the Season Pass, so I kinda got forced to after 1.3 came out.
Gotta be said, Underground is pretty fun. For an hour or 2-3. Then it tends to get repetitive and just another grindfest.
High level yellow and greens drop often. Kind of negates the hard work people had to put in before 1.3.
Oh well, I'll just play when I have 20 minutes to spare and do an underground mission. It's still a fun game to play, if you keep your expectations low. Also helps alot if you play with multiple team members.