The one big downside to processing at elevated temperatures and abbreviated times is the loss of precision in control. Working at high temperatures is fine and dandy if you are aiming for "printable" negatives. If your goal is to do N+1 or N-1 development and your base time is 3 minutes (180 seconds) then your N+/- factor is a mere 18 seconds, which is within the margin for error of pouring your solutions in and out of the developing tank.