As a fellow salesman I would have thought you would recognize a salesman blowing smoke up your butt?
Aside from the fact of Beefmaster having a long, successful, breeding program... saying that you can cross two composites and get more consistency than one composite is not even logical. That's probably the reason for most people using Hereford and not Braford. The Hereford will bring some uniformity to the gerts.
That cross is no more capable or less capable, from a breed stand point, than any other cross. They are good cattle with a lot of eye appeal. Red motts with ear with always sell.
Any time I hear some one put that much emphasis on breed its a red flag that you are getting a sales pitch.