You know there is one big problem with flying a different mode:

When you want a pilot better than you to help with your model wether its trimming, or in an emergency you are not going to get the help you need or want.

Then again if you are already the expert then this should not matter.

There have been TOC, Nationals, World Champs flying Mode2, flying Mode1. I don't thing the mode has much to do with the how well you fly just that you do.