Vox VTB-1 Treble Booster

I bought the VTB-1 mainly to use with my Vox Mini Superbeetle and a Tele, and so far I’m really enjoying the combination. It adds a very noticeable amount of bite, presence and harmonic character without just making the amp louder. The sound becomes more aggressive and lively, particularly when the amp is already being pushed.
With the standard setting (Fat deactivated) you get that classic bright, cutting treble-booster character, while the Fat setting adds some useful body and makes it easier to get a fuller sound.
What I particularly like is how it interacts with the Vox character rather than simply sounding like another overdrive pedal. There is a definite increase in attack and upper-mid presence, and backing off the guitar volume gives you more control over the amount of drive.
I also have a Vox AC15 at home, which I haven't tried the VTB-1 with yet. That's actually one of the combinations I'm most interested in hearing, given the classic Vox/treble-booster connection. Based on how well it works with the Mini Superbeetle, I'm expecting it to be a very good match.
So far, very happy with it. If you like the Vox sound and want to push it towards a more biting, harmonically rich overdriven tone, this is definitely worth trying.