A small report from one day of playing the pedal, which is in my case not nearly enough to get to the bottom of it:
The first thing that becomes apparent is how well it reacts to playing dynamics and, as an extension of that, how great it feels to play.
I know the people who claim "The tone is in the fingers" mean the exact opposite, but with the Becos, a lot of tone is actually placed into your plucking hand.
The perceived (by me, that is) dynamic capabilities exceed what you'd expect from a Tube Screamer. Sure, those usually are quite good at reacting to playing dynamics, but this one here is not quite good, it's excellent!
True to a TS style pedal, it's perfectly centered in the middle between what we call "amp-like" and "pedal-like" response. An amp-like pedal pushes back when you push it. A pedal-like pedal feels like it's gonna take off on its own and you need to reign it in. The Tube Screamer hangs in the middle between all that and offers no momentum of its own, yet it goes with your flow like a palm tree in the wind. The Becos takes that nature one step further. It'll easily follow your lead and there is barely any resistance to overcome, yet the magical connection between fingertips and ears is all there. Play for five minutes and you really feel how the pedal will react to your playing before you hit the note. It's just the slightest bit gooey. Not like 15W40, but more like the stuff they use in F1 cars. There's barely any friction, just enough to provide feedback (probably not if you're ham-fisted, but ham-fisted people are rarely interested in provided feedback due to their ham-fistedness).
I already said there's a learning curve attached to manipulating mix, dryEQ and gain into providing the perfect tone. Let me elaborate on that:
It's three knobs, and there is interaction. It is quite predictable and linear once you get used to it, but basically it means when you change one of them, you need to touch the other two to balance the change. This leads to a mild case of choice overload, because you're constantly feeling that while you're in a good place already, one more minor tweak gets you to an even better one - and it often does.
Next up, the diode selection. As I already said, you get the choice between 1. Silicon, 2. Silicon but asymmetrical and 3. red LEDs.
For me personally, this usually means there is one clearly favorable option and the other, lesser options that were put in to satisfy other people than me.
Not so in case of the Becos, because they all sound great. The LEDs are somewhat tamed (compared to what I'm used to from LED clipping which usually sounds quite chaotic to my ear). The Silicon clipping is smoother and has the densest texture to it, with both the LED and asymmetrical silicon have a bit more air between the drive chunks. At first, the asymmetrical silicon sounds a bit like a lower gain version of the standard option, but five minutes in I realize there's a different texture to it. This is in equal parts great and terrible. The part of me that wants a simple pedal with one clear sweet spot is pulling its hair while the part in me that enjoys a well made drive pedal rejoices in so many options.
I do think the same goes for the Deep switch. It's not a "if you play bass, you want that always on" type of switch, but an option to lend the drive part of the signal more heft.
I'll have to play some more to verify other suspicions the pedal hinted towards, but right at this point I want to say that this is one of the best Tube Screamer variants I ever played. I can recall the recently released Broughton Evergreen, which I found to be good, but somewhat bland, if not to say generic. The Way Huge Green Rhino MkV is a great pedal for it's 100Hz boost and the unusual density my signal gained and by which it was held together in a brutal mix. And of course the BlueBoy Deluxe, which got completely forgotten because empress released the Drive and that was clearly more exciting. I'll A/B the Becos and the Blue Boy when I get more of a feeling for how to set the Becos properly.