Interviewers describe company as a wild west that will suck the life out of you. How seriously should I take it?

Dear wonderful community members,

I've been handed a job offer from a company which is a rising star in its field. The new position is pretty much what I'm looking for but the company culture seems intimidating. All interviewers I met, directors, VPs and EVPs have tried to scare the hell out of me about how difficult working for them will be. I convinced them that  it shouldn't be a problem but now that I'm left with the decision - I'm not sure if that's really the case.

How seriously should I take their signs of warning? Are they merely trying to intimidate me or is it really so awful?

Some quick background:

*  Currently a first line engineering manager for a multi-billion dollar tech company with 50K+ employees. Company is fairly bureaucratic, mostly everything works according to well established processes, I have plenty of influence and I run my own little domain. Work hours are long but reasonable (normally 52-56h a week). People are good.

* I'm secretly seeking other opportunities because I want to acquire marketing skills and change the overall environment. Getting tired of engineering and not interested in any "organic" promotions at my firm.

* New position is a technical marketing manager (no direct reports), compensation is a bit better, company is public and so far growing enormously. 1K employees.

* I've become a "Manager Tools" manager. Very ethical, orderly, organized and calculated. It resonates very well with the current company.
My DISC profile is 7007. high D, high C. I love making constant progress and decisions. I'm also thorough, very organized and not a huge fan of constant changes and sudden shifts.

* According to what I've been told by managers at the new company, this is what their culture is:

   -- CEO is extremely forceful and dominant. Has his fingers in every pie. Constantly overrules decisions and gives very harsh personal feedback potentially to everyone in the company. EVPs and SVPs have also adopted this (dubious) style. Very different from my current place.

   -- Company runs like the wild west. Dominance is often the only way to get things done and reach agreements. Few processes exist and even those are in serious need of fixing. Role power is only reserved to senior management. The chain of command is inconsistent. EVP can communicate one thing and a few minutes later the CEO will overrule it. You won't make an impact unless you have very clear presence. "Be prepared for many personal attacks in meetings." , "Your present company and us are on opposite sides of the scale"

   -- Expected commitment is total. "Since I've moved here I have no life outside of this place". "Managers and sales can call you any minute of the day and demand immediate action. We work with customers from any conceivable time zone. Fire fighting happens all the time". I don't know how many work hours and mess this translates to...

   -- Direct manager says: "I get 500 emails a day. Things will fall apart unless I'm on my blackberry at least once an hour". Sounds bad to me. I strive for e-mail once a day, although I usually get only 50/day.

July-17: Thank you guys, helpful advice! I eventually decided not to take this job and you helped me reach this choice. 
P.S. there is a technical issue with the forums preventing me from publicly responding to messages.