I'm not qualified to comment on the efficacy of NIMS in a large scale disaster, only small ones (fires, floods). NIMS does function very well in incidents I'm involved in though, in terms of creating a more structured and effective interface between responding agencies (e.g. Fire Department and Red Cross). Some random thoughts on NIMS in smaller-scale practice:

- you get what you train for; the quality of an IC can vary, how seriously they take the whole ICS process/protocol. Good ICs are focussed - sometimes overly focussed, 'no time for other issues' on 'non-NIM' aspects of the response; better ICs can churn in downstream planning (what to do with apartment occupants) into the disaster (putting out the fire); the best ICs recognize opportunities to delegate tasks to outside agencies (like sheltering victims) immediately, and have the confidence to know they'll be addressed. NIMs works pretty well when you have the resources and the confidence to organize your response well.

- training and actual experience among responding agencies is golden. I know and the IC knows that when I see "J Madson" on the back of one particular IC that I can report in and get started doing my Red Cross job; we know each other, know what to expect from me as my function, I stay in my lane and get my tasks done without alot of oversight. You can never train (enough) effectively for large scale disasters, you have to trust that your response will scale up.

- when you improvise is an age old dilemma. Most will say improvisation and adaptation belong at the very local level, not at the top of an incident command. There is alot to back that up too. As a local responder I want the freedom to depart from NIMS and improvise and adapt my response - I don't want an IC improvising and adapting too much. There are lots of expecations, from the public, press and from responders in general. Don't do something that is obviously asshat, but don't depart from established protocols too far or too often either. That way lies chaos..

- scaling out any response is tricky; if not NIMS, then what? NYC's modified NIMS? I'm fine with that - I assume it incorporates important lessons learned, and probably some local resources dropped on responders courtesy of Homeland Security. Mind though the risk that you would develop your own NIMS that no one else can play / participate in effectively. Especially in large scale disasters you need thousands of responders to come in and work effectively, right away - they shouldn't spend time stumbling over a 'NY Way' versus a 'Boston Way' versus a 'Omaha Way'. Bad juju...

- in criticizing NIMS, why is the first impulse to talk about Katrina and FEMA (Brownie)? That's 5 years ago, donkey years in terms of refining response protocols. FEMA has changed (for the better), NIMS responses have changed as a result of lessons learned from Katrina - we make mistakes, we learn from them, and move on.