Gifford,
I was about to use my DX6 for full range activities, but I broke the Tx. I used this opportunity to go ahead and upgrade to the DX6I.
Before I did however, I asked this same question on here. Someone replied that a bunch of people in his club, including himself use the DX6 for full range and do not have problems.
Your plane though. You can give it a shot and tell us how it goes

lol
If you can please post if you do try it, I am curious, as I am sure are others.