Of course, no product is going to suit everyone when it comes to sound and/or system compatibility, so I make no claims that way. However, one thing that I do feel is true is the reliability and support that Atma Sphere provides in their product.
Two things to potentially consider in regard to the issue at hand:
1) Atma Sphere used to offer their amps in kit form. Obviously, once someone undertakes their own build, all bets are off. At that point, the final result reflects the builder as much or more than the actual product or company providing said product.
However, as that time was both very long ago and very recent, I would guess this pair of amps didn't come via the kit route
2) A lot of people over the years have modified their Atma Sphere amplifiers. Again, using the kit rationale, at that point, what comes out of that now more aligns with the person performing the upgrade, as opposed to what they started with, or the company who manufactured the product.
I'm not saying one of these two scenarios explains what happened, but they are two possible explanations to add into the mix.