BLUF: This is a good travel/quiet practice pedal that can handle stage use. I don't reccomend this pedal if you're planning to rely on the OD and Fuzz channels.
I got this preamp to take with me when I travel. It fits in the case with my Steinberger without much drama. As a headphone amp it performs fantastically. It's strong enough to cleanly push my MDR-7506s to their limit (this a rare feat for most amps). It has my favorite kind of Aux system: direct passthrough. Volume is set at the source, which keeps the complication to a minimum. I find the cab sim to be very subtle, but Modern cleans the tone up a little to my ears.
Tone shaping is pretty good with wide range on the mid knob. I use it to tame some of the string noise on my UBass, which also sees travel time. The blend knob works as advertized between the bypass and wet signals. Lastly, the unit powers on when plugged in, or when a cable is plugged into the instrument input. As of right now I don't know if there's much of a parasitic drain on the battery.
The drive channels suck.
This pedal has an annoying limiting system. There's a limiter on the input, but it seems a bit low seeing as the passive pickups on my Steinberger need to pad to keep out of it. Thankfully there's an led that will help you tune your volume. However, this could be problematic if you're the kind of player that messes with your instrument's volume a lot. The second limiter is the poorly named Saturation knob. I keep this pretty low because when your signal hits the threshold there's a large drop in the whole signal. In other words, it reduces the total gain instead of cutting the signal above the threshold. Your dreams of gated fuzz are not going to come true here.
I might toy with the drive circuit at some point. The cruddy drive sounds are probably from poor choices of components.
Palmer Bass Pocket Amp
Preamp... headphone amp... effects pedal... direct box. All in a footswitchable box that can be powered by a battery or an adapter.