I don't have a problem using them with "trad" equipment. The friend I hunt with has lost 3 birds in as many years with big fixed blade broad heads after seemingly good solid hits.
I on the other hand have hit and killed 4 birds in as many years, with 4, 3 and 2 blade heads without a lost bird, and they all died in sight, no not a great feat, but it all just depends on the shot and the bird.
I do have to disagree with the idea that with a Bullhead it is either "a dead bird or a miss". There is still that possibility that you could just slice the bird in a non fatal fashion and it flies off wounded, or fatal fashion (and still fly off) and loose that bird if later he bleeds out.
My point is, there is no fail safe method, but using a Bullhead may improve your odds of bagging that bird...no different (as already said) than using a modern blind and modern bow to up your odds.