I have a friend of mine that is getting into helis also and he wants a DX6i so I'm thinking about selling him the one I just bought from this site and putting the money toward getting a DX7, DX7s, or DX8. Any one of these particularly better than the other? I mean aside from obviously more channels. Also is a DX7 still a good TX considerign they have teh DX7s out now?