Range itself isn't the issue with the 6100, shadowing is the problem. If you're flying farther away and the engine for example, comes between the receiver and transmitter, you could loose signal for a short time (or worse). If you never loose line of sight between the radio and the reciever you would have control beyond what you could see it to fly.

Same scenario with something with a satalite reciever, and as long as either reciever has a good lock then you never know there was a problem.