JackStar07

The FS8 uses a "built in" reciever it only comes in 72 Mhz (not currently 35 Mhz as previously posted) it will not work with the Spectrum DX7 or any other 2.4 Ghz radio since it is outside that radio's frequency. The FS8 is more configurable than the cpd4 and it has many addons for it that may or may not suit you.

The CPD4 utilizes Your existing reciever. It will work with any model that uses 2 Servos (One Roll and One Pitch) including airplanes and Helicopters that have a single roll and a single pitch servo. There are no addons for the CPD4. The CPD4 is very basic but that is why its only 70 bucks. There are More advanced systems out there but you will pay more for them as well. The CPD4 has worked Very well for me. I have not tried the FS8 nor do I intend to since The CPD4 is all that I really wanted in the way of Stabilization.

The CPD4 uses IR sensors to find that Level position and must be calibrated before each use. Calibration is very simple and quick to do. The better you get at leveling the Model during calibration the Better the stabilization will be...

Since the CPD4 uses IR it does not do well in enviroments where the temperature difference is to low such as in doors or at night. Do NOT use the CPD4 inside... you may crash.

I use the CPD4 with the Spectrum DX7 and the AR7000. I think Ralph is using the AR6100 and the AR6000 on tow of his models with the DX7 and the CPD4 with no problems as well.

The Only issue I have experienced is that I work at an Active Airport and they have radar on the airfield. The radar is normally off on the weekends. but during the week if I do not wait till later in the evening it may be on and it causes glitching becuase of the frequency band of the dx7 (2.4 GHz) I dont think you will have any issues away from radar sites.

The FS8 will NOT work with the DX7 since it uses a built in 72 MHz receiver.

I hope this helps