I am sure that the new designs all have something over the older ones, whether it's using composite materials or better aerodynamic designs.
I have been told by a good friend that competed allot when he lived CA the the biggest advantage you can have is to practice. I am also going to compete this year for my first time and have been reading everything I can on the subject. What I have been finding is to make sure your plane is trimmed and balanced properly, (Model Aviation has a great 2 part article on this in the February and April issues under Scale Aerobatics). The second thing is to fly the sequence, as often as possible. And not 10 times a day but a couple times per day, as many days as possible. I am going to try that approach and being no expert myself I will have to let you know if its working or not, it seems to make sense though. Good luck in your competitions.