I think for competitions the choice is a little different. You want to remove as many variables as you can from the process. This is why many of the more serious comp teams buy branded beef that is a little more highly graded. It is also, I think, why Wagyu has become so much more common, despite the cost, as the product is just a little more consistent.
Many teams do well with Certified Angus Beef or other similar branded beef, with Choice grading, again removing some of the variables.