I'll be curious to see what role they play. I took a formation on a run to strat yesterday, no big reason, it's just something to hit (FIX THE STRATS). Took them up to 33k and slipped between the radars to drop my cookies. Headed strait out over a few radars, I'm not sure if anyone tried to come after me, I saw a dar bar or two, but they never would have caught up with me. It takes a long time for you speed to settle out, similar to the 234, so that has to be planned. I know when I hit strat I had to turn rather sharply to get my target and the bombsite was wobbling as the plane tried to stabilize.
It doesn't take long to get to a good altitude, especially if you're a bomber pilot used to flying 17s or Lancs.
There is really no advantage to a tight formation like the 91st would normally fly. With no guns all you are doing is giving any attacker a buffet of kills.