Welcome to Librarium Online!
Im thinking we should compile pros and cons of each Formation and personal experiances with them. Then we can all know what worth it and not. Ill go frist.
Can be cheap to field. The Special rules can make it become pricy but i like the fact i can feild a few 20 man sniper teams. Also a shaper with wytch blade is nice i have downed dreads wih it before.
Armored Interdiction Cadre
Its a great boon to have extra markerlight token to place anywhere you see fit every shooting phase as long as the command tank is alive
Then the only other apoc deal i have used and can comment on is the Tigershark AX-1-0 and what can i say heavy railgun on a flyer sweet.