Well having gone through the issue with the same idea in mind, I'll offer a thought that I've since learned in playing with heli's;

You can't just put the numbers from on tx into another tx and have it work with a heli. The settings are just too critical. If you're going to change radios, then you need to go through the setup with the new tx. Going from a similar radio like the DX6i to a DX-7 and using the DX6i's travel settings will get you close, but close doesn't work on a heli as you've found out.

Oh, the other thing is that even with the same hardware, one guy's settings won't be exactly the same as another's.