My KWA has been running for a couple of weeks now and is opening up nicely, most of my listening is at the opposite end of the spectrum to that carried out by Srajan in the 6Moons review - in my case low efficinency speakers at high volume levels. I have run the KWA at lower volumes and can repilicate the review comments that it is capable of delivering a full quality sound at low levels, predominantly this has been with the KWA set to the higher bias level. I find most amps struggle to adequately perform like this at lower volumes.
In terms of raw decibels the KWA 150 is able to come very close to my 500 watt MF amp, but has a deeper and more controlled bass slam that is remarkable. I have not heard the Spectrons so it will be interesting for Ted to see how it performs.
The most adequate metaphor I find for the KWA is auto related: when I first moved from Europe to the US I was determined to buy a muscle car but found that they certainly gave me the straight line A-B speed but lacked the handling, normal driving finesse and quality that I was used to from a German brand such as BMW/Audi/Porsche. The German brands gave me the quality, driving around town comfort, high speed handling and straight line speed I was looking for. I see the KWA 150 along the same lines, it's excellent at all volume levels, capable of performing with the whole gamut of speakers designers and has the style, quality and looks to go with it.