Is the Hegel unit a new unit? Do both amps have the inputs and features you require? The Hegel has a plethora of digital features that the Gryphon omits. Is that important? Your choice can also depend upon where you live. If either unit breaks is there a quality distributor to handle service? The Gryphon probably has a higher performance ceiling, but whether that can be achieved you will need to take into account your other components.