Yes, I've heard it - in fact I bought one last month. (I'm not suprised that the US distributors have run out - shows what the power of a positive review can do.)
I like it a lot, and in fact I've been planning to post some impressions of it here, but the problem is I haven't heard any really good amps to compare it to. I've directly compared it to a Pimeta, and it's way better, clearly in another league (as it should be for the price). Also, from memory, it's a lot better than an X-Cans V3. The sound is sweet but quite detailed; the sound stage is awesome and musical timbres sound very realistic. I wouldn't say it's flawless though; for one thing, at the high impedance setting it has a slight hum; only barely audible, but it's defintely there. It's also responded well to my first attempts at tube rolling; replacing the EL84s with JJs and the 12AU7 with a NOS seimens tightened up what was a somewhat slow bass.
One other thing to note is that here in Australia I could get the Cyber-20 at a much lower comparative price point than it sells for in the US; it cost me about the same as an MG-Head DT OTL. In the states it seems like there are a lot more good amps at the same price point as the Cyber-20 (like the Earmax and the Singlepower PPX).
Nevertheless, I have to say, it's rocking my world; with my HD-650s, it's the best setup I've ever heard, by a long margin.
