Originally Posted by despegue
Any additional task to accomplish in a high workload environment is adding to the risk of forgetting, omitting or incorrectly execution. With packs, this can be potentially very serious.
I am talking B737 here, not Airbus or better designed Boeing types.
Well, a single switch movement on 737 at least temporarily solves many problems related to forgetting to restore A/C configuration after bleeds off (with APU) or unpressurized takeoff.
Just put the right engine bleed switch to ON when passing 1000ft and the aircraft will become pressurized in case of unpressurized takeoff or continue to become pressurized even if you shut down the APU before reconfiguring the bleeds.
Now, whether your company thinks this is more dangerous than postopning the entire C pattern until safe altitude - that's a different problem. As for passenger comfort goes, you always have the option to taxi with packs on the engines and reconfigure during line up - although I don't think this is a very good idea, safety-wise.
Back on topic: in my opinion, it is more safe to do FLEX + packs off than to depart with full TO thrust just for the sake of having bleeds/packs on for takeoff - if resulting PLTOM is the same. In case of full thrust + packs on you don't have any spare thrust margin to use, if you would really need it - except firewalling the thrust levers. If you depart with FLEX + packs off, you can still press TOGA and receive some extra thrust without overstressing the engines.