It's a smart move from Bogner to offer the Uber mode also on the first channel so you can just have two flavors of high gain rather than live with a less than stellar crunch channel for example.
Yeah the mode switches that add and take away gain stages are really cool. The first thing I thought when I saw them was that Bogner must have liked the Helios Eclipse enough to apply that design to the new amp. In the Helios Eclipse, the two gain channels each have three modes:
Eclipse Ch2:
Hot: standard number of gain stages
80's: standard number of gain stages + silicone diodes
Eclipse: standard number of gain stages + two more tube gain stages
Eclipse Ch3:
Hot: low end filtering + standard number of gain stages
80's: low end filtering + standard number of gain stages + silicone diodes
Eclipse+: low end filtering + standard number of gain stages + silicone diodes + two more tube gain stages
If I had to guess, I'd say that's probably very similar to how the Uber Ultra will operate. The Helios doesn't seem to have a lot of street cred as a modern high gain amp, but it can easily do those tones if you boost it the slightest bit and cut just a bit of bass at the input, and when I did that it became one of the best high gain setups I've ever played, even for modern metal. Truthfully though, if I had my way it would have just a bit more low end. I've also heard the new Uber is just a bit more Marshally in attack than the old Ubers, which were more designed as an answer to Mesa's Rectifiers. If the new Uber Ultra turns out to be a a mix of a Helios preamp on steroids and a OG Uber style power section that can shake the room with unfiltered sub low end like the OG Uber could, then it could be a seriously killer amp.