Outside of a couple of static teams (both of which fell apart by level 30), I haven't done missions on a team since around Issue 10 or 11, and I played until sunset and started on Homecoming on its opening day. I just don't see the point in it. You don't get any reward merits, you tend to outlevel stuff that you actually want to do, you're usually rushed and forced to skip all of the text by people who just "want to get to the action," and I don't enjoy most blue side content to begin with, (which is where most of the mission teams are). I run all missions solo. If I team, it'll be on Strike Forces, Task Forces, Trials, Incarnate Trials, and raids.