Hello,
a few months ago I build the Etherwave Standard kit. Then I started to work with the method of Victor Estrada. After a few weeks I began to feel a little bit secure.
Then I saw a video of Carolina Eyck. The 8 positions looked difficult but I decided to try it. I bought the book and tried her method. At first it was very hard. I could not find a good starting position. Now a few weeks later I noticed that when I have found the starting position I can play the scale. I also discovered the nonlinearity of the Etherwave. I find that for me playing the scale upwards is easier the playing downwards.
The method of Carolina helped me discovering the possibilities of the Etherwave. But I am still searching for the steady handpositions that will work for me. I notice that I am using slightly different positions and I find it difficult to work with the combination of the fingerpositions and the bending of the wrist.
Today I have build the ESP01-module in the Etherwave. That is a great improvement. The Bassrange is expanded, the sound has changed (I like the new sound) and I think that its more lineair then it was (I am not certain). I can recommend the ESP01-module.It really is great.
Meanwhile I look at the dvd of Peter Pringle and I think that I am going to switch to his method. I like to improvise and it seems to me that the four position method will be more useful for my way of playing.
And yes, the theremin is very difficult the learn but it is very attractive at the same time.