The ADAM's distortion is quite strong, so having the extra compression on the clean channel helps to keep the cleans at the same level as the distortion (since distortion causes compression by itself). The Photon's distortion works well at lower gain, so the clean channel can stay completely clean. The ADAM's distortion is unique, and it's possible that it can't be reproduced by traditional analog methods (but I'm certainly no expert on that). The Photon has a more classic sound to it since it's based on an analog circuit. Neither of them is inherently better, it just depends on the sound you are after. I aspire to be able to play the fast Nolly-style prog metal, but I spend most of my time practicing more classic songs where the Photon works better.