There is a lot more to the DX8 than just the telemetry, the ability to adjust your retract servo or flap speed via your transmitter for example, that save's on separate modulus to achieve the same goal (ie less links in a chain that can fail), great features should you see yourself getting into larger scale aircraft down the line.
Digital radios are more than just moving a servo in accordance to how you push a stick or button, it's about good programming that enables your to get the utmost from your plane, and the hobby in general. As a rule, the more channels, the more advanced and beneficial the programming within your transmitter.

This is yet another reason behind my personal view that you SHOULD get the best radio you can afford (aside from lack of need to upgrade so quickly)