Hi:
Kees's order form only comes up at certain times. It took me about two months before I was able to get my order in. There seems to be nothing like a pattern or certain time as to prescisely WHEN the form appears.
I did get the order in and did receive the theremin. Right now, it's the only one of five theremin I own that's set up -- this is to allow time to get used to playing it. If the Kees is your first one, you're starting at a good place. It's very responsive, and hooking it up to a decent amp will allow you to get some tonal variations and timbres that the instrument itself is unable to do. The timbre knob has two "click-in" settings only: SAW and SINE. Instruments like the Theremax, Etherwave standard and the Etherwave Pro allow for continuous "dialing" on the waveform and brightness knobs, for a much wider variety of sound textures. As I said, an amp can add in the ability to augment the timbres.
However, this being your first theremin, you'll be fine and have a lot of fun. It's priced very reasonably, It's easily portable, it looks very nice, too.
I'm sure you'll enjoy it when it arrives.