Detention Field is handy if you'd like to single out an AV whilst you clear it's bodyguards that could be life threatening, after that staggering Alpha-Strike.
Also Repulsion Bomb is handy for Blasters who suggest they Tank, or Defenders that suggest they Scrap, and get themselves abit overwhelmed.
TBH if you want to give extra defense to the team to add to your bubbles, get Grant Invisibility, it would probably then let the Blasters Tank and Defenders Scrap! 
Well, that is what I intend to do on my */Force Field Controller, for maximum survivability for the team.
Thanks for the advice, I ended up getting detention field. Figured it would be handy for AVs and also in PvP.
Personally I would'nt skip Dark Pit, teamed with Tenebrous Tentacles you have the closest thing to an aoe hold a non-Radiation Emission Defender can get. Its not quite up there with similar Controller aoe Disorients but with a bit of slotting its well worth it. Mine has 2 acc, 2 disorient duration and 2 recharge.
Hi all,
I've come back to my FF/Dark Defender after a long, long time. I haven't played her since she was on the American servers a while back.
Now, I'm giving her a respec obviously to get rid of the six slots in her bubbles etc.
My problem is that I am stuck on a power to get. I have all the bubbles except detention and rep bomb and I have all the blasts except dark pit and torrent. I have hover, fly and the 3 fitness powers.
I have no idea what to get as another power. Things I had in mind where hasten, stealth or maneuvers. Maybe even detention field.
Anyone advise me on what they think would be most usefull?
Cheers