If you look at the ICEpower website, they explain that the ICEpower amplifier module is effectively a cheap and efficient building block for a bespoke design, typically by adding an improved power supply.
You can buy a pair of the building block ICEpower 1200 AS1 amplifiers and all parts in a kit for $600.
The nCore and iPurifi amplifiers are much more popular as you can buy separate power supplies and install them with little or no modification. Many manufacturers do. The are a lot more expensive, I think each nCore 1200 amplifier unit is about $250 and he power supply the same again.
In the UK a pair of mono boxes with the nCore amp and power supply installed cost exactly half the price of the M1200.
So I wouldn’t worry about the fact that the ICEpower boxes are mainly fresh air and and the basic boards are very cheap. What you are paying for is PS Audio’s valve input stage and a nice box.
Had PS Audio just put nCore components in a box, it would have been just like any num her of other nCore amplifier, as they are rarely modified.
The M1200 has been well received in the UK press and also the S300 had a good review. One day I would like to hear the M1200, not for the power, but for Darren’s valve twist to the Class D approach.