As far as I know, in Class-D amps, Hypex is the only credible competitor to Nuprime today, and there are fundamental reasons that we have moved passed them:
1. business model - NuPrime is in the business of making our own amp at whatever cost/price we want to push. So in that regards, we can continue to push the envelope of class D amp design as we see fit. The result is rapid innovation that resulted in many variations of amps, and finally Evolution One (unmatched by any amp regardless of class).
Hypex on the other hand, is in the OEM business. i.e. designs are made for cost and volume considerations. It is not in their business to design something with only 500 units of annual production. That will not make financial sense.
The difference is between a high quality restaurant chain versus a gourmet restaurant.
2. Companies who are using Hypex modules can only do incremental improvement - sure, it can still be quite dramatic improvement when you upgrade the power supply, Opamps, some passive components along the signal path.
But common sense tells you that these can only be incremental improvement. You can't change the fundamental design.
In our opinion, the most advance Class-D amp like the Evolution One has already surpassed almost all Class A, AB, tube designs. Those technologies can only go so far relying on device characteristic.
In the most advance class-D design, we can combined device characteristic (ie using Class A transistors circuit) with innovative architecture.