So I had a little spare time to make myself a new toy...
The Multiplex Fox is originaly made to be a simple free flight throw glider. But a quick search on youtube reveals that it is a good starting point for add-ons like radio control and motor.

Model Specifications:
Material: EPP

Finaly I found a diserted football field (150x175m) to perform the test flight.

As can be seen - The test flight went very well and few conclusion where drawn:
1. The elevator control movment range was increased
2. The C.G. moved a little more to the back.
3. Normal flight should be made with half throttle
4. Rudder control should be added for aerobatics and precise flight
5. The model can fly in low winds but it is much harder to control
6. It would be nice to change the receiver to something smaller and lighter (~10g)

I had few more successful flights and decided to add the following:
1. Rudder control - 1.5gr Micro-Servo + carbon push-rode Total of 3gr.
2. DVR Unit + DC/DC (optional) - 15gr.
For the DVR Unit I used the simple & not expensive key-chain Spycam that can be found on eBay (20gr). I disassembled it and used the bare PCB (9gr). The DVR needs ~3.7v / 200mA to operate. Hence, I needed to add a DC/DC converter (2gr) for high efficiency conversion of the ~8v LiPo (or 5v BEC) to ~3.7v. There is another option which is to drive the DVR directly from the BEC (5v). I tested the DVR with 5v input and it worked fine but I am not sure that the DVR design is rated for 5v input so I am usind a DC/DC converted.

On the new flight I noticed the following:
1. I must use full throttle
2. The flight must be done with very low or no wind at all.
3. The model tend to stall very easy.
4. After 13min of flight the 2cell Lipo batt was ~7.6v. After a full charge - the charger reported a 500mAh of charge. Hence, the average current consumpion was ~2.3A.

I think all the above simptoms are caused by the relativly high weight of the model (x3 from the original design).
Since the lift force relation to the air-speed is a power of 2. It means that the typical speed of the model was increased by ~x1.8 and the drag increased even more becuase of the "not so aerodynamic" body changes I had to make.

I don't want the model to fly any faster. Hence changing the prop & battary configuration in order to gain more thrust is, currently, not an option.
Instead, I am planing to make the following changes:
1. Change the current receiver to CORONA 6CH micro Receiver RP6D1 - 10gr ( -25gr)
2. Assemble the two LiPo cell inside the model body to reduce the total drag.
3. Change the Alieron push rodes setup to be like the rudder push rode in order to reduce the total drag & weigth (-2gr).
The expected typical speed of the model should be x1.6 and the total drag force will be reduced even more. Hence better climb rate, wind resistance & flight time. 
 

The CORONA receiver should arive in 1-2weeks so the first enhancmet is to assemble the batteries inside the model body.

It is amazing how it improved the flight Characteristics!! The model handles medium winds much better+ when there no wind it can fly with 1/2 to 3/4 throttle.

The last video is of  a low altitude flight that ended with a crash. As can be seen there are high voltage power lines in the field. I "Successfully" Crashed into one of them... The propeller broke free and it took me 10min to find it. But other then that everything is o.k.

Now I am starting to wonder how to improve the DVR picture quality:
1. Camera placement
2. Camera vibration dumping / isolation
3. Clearer protective window for the camera
4. Lower the angle of the camera toward the ground and try not to include the propeller in thr FOV

This video is the best of all to this point. I removed a part of the cover in front of the camera and took-off.
The picture is much clearer and I didn't notice degradation of the flight characteristics.