Nice and compact. The heatsinks are quite small, have you measured, monitored the temperature of heatsinks when driving 1/3 power at 4 ohms load for some period of time..?
It all depends on Ibias. With 500mA Ibias at low output the temp was 42grdC. With current Ibias=100mA temp is 31grdC at low output and goes up to 55grdC at 30Wrms. But that is already very loud.