Hello Marco,
I've used Ditex servos on my latest F3A model and I'm not exactly convinced of them.
The TD0606 is no longer available. In addition, it gets very quickly a relatively large bearing clearance. The bearing clearance of the larger servos is very good.
Furthermore, the servos have a high power consumption. In my opinion, much more than others. If you are not using a BEC, you should be careful with the receiver battery here.
In my opinion, the price / performance ratio does not fit.
The servos are very noisy in the zero position and regulate here continuously (specially the TD0905).
I use the TD0606 on elevator, the TD0905 on aileron and the 1609 on rudder.
In any case, I will soon throw out the TD0606 again and consider me to replace the TD0905.
I'm going back to Futaba.
Gerhard