Our company does a lot of max weight TO's and we see more than our share of red lights at the end of the runway. If, at that time we have a nose heavy load and the trim doesn't reflect this, well, we have a few less red lights to worry about untill they get fixed and then we have some "splainin to do Lucy".
one of our problems is, we get TWO different trim settings, one from our weight and balance sheet and one from our performance sheet. The W&B seems to me the more accurate one, but some folks like the performance setting. these can differ as much as 1.2 units. thats a fair amount on a 747 but very recoverable; just puts the performance factors out the window!
Its not just a job, its an adventure!