I posted this in the Synergy thread also. I think they both sound great here. I have considered an UU, but not sure if it is worth the $3k vs the Synergy module.
He liked the amp a little better, but I have a feeling they would be even closer if he used a better power amp than the Fryette Power Station.
In that video I liked the amp better but they both sounded really good. The head has a clarity and assertiveness in the high mids I didn't hear in the module. However it's also not an Uber Ultra module, it's an OG Uberschall module so I'd expect there to be some differences. I bet if you threw a clean / treble boost in front of that module they'd get much closer.
I have both and enjoy both. There’s more variations in sound with the UU. I think I can get the UU to sound like the Synergy, but there are sounds in the UU I can’t get from the Synergy. I play the Synergy Uber 90% of the time on one setting when I just pick up and play, it’s just my go-to.