Trinity Prime is an interesting choice, as she’s not a damaging frame but is a potent healing and support frame. She’s a bit squishy, which is worth considering when running solo, but in groups she can be an exceptionally useful support character. As with all version, the Prime variant is far more powerful than the base version, so you’ll be getting access to a potent healer in her best possible incarnation. Who wouldn’t like that? (Aside from the enemies your frames are fighting, they would probably prefer no healers.)
Warframe or may want to play some Warframe, you can get something very valuable this month with a free Trinity Prime frame. Just link your Warframe account with your Twitch account, and in addition to the special syandana (read: cape) that you normally get, you’ll also get Trinity Prime as a new frame option.
Source: Twitch blog; thanks to Alex and CapnLan for the tip!