This is something that we have discussed over and over again and that's servo end stops or linkage binding. It really makes a BIG difference in how the receiver will perform as well as how well the aircraft responds to inputs, and of course, the longevity of your aircraft. You don't want your receiver taking a nap caused by a bind in the linkage while flying the plane.

If the linkage binds, the action will be sluggish and be a big drain on the battery pack. In addition to this, if using a 2.4 GHz system, as John mentioned earlier, you take the chance of having the voltage dip below the operating threshold of digital receivers. And, that doesn't matter if you are using Spektrum, Futaba, JR, Turingey, whatever.. that threshold exists. Revovery time varies, but that's a chance you just don't want to take.

Any and all binds, including those caused by end point mis-adjustments, espeically with the throttle, really must be resolved before flying the plane for the first time. You just don't need something that can be avoided to interfere with the maiden flight.

A simple flicker of the LED's on these devices when the sticks are moved is perfectly normal. BUT, when you move the sticks, and the LED's go to the red, this is an obvious indication that something is binding or that a servo is straining at it's end points. As I said, end point problems are usually throttle related. Other binds can exist in the linkage. Regardless, they must be corrected before you fly the plane.

If everything is working ok, and there are no binds or end point issues, well, these devices are great for a quick sanity check before and after each flight.

CGr