I bought it mainly because of the headphone output and the “sweepable” middle frequencies and I am not dissapointed!
The clean channel sounds amazing with both my active and passive basses. The controls are super responsive and give you a lot of possibilities, and the knobs feels sturdy. The FX insert is a great idea to save space and the other features like speaker emulation and headphones output sound really good.
I deducted points because the Overdrive and Fuzz channels are too mild in my opinion. In order to get a good crunchy sound out of them, you need to crank the Drive almost all the way up (I go all the way!) and use the Normal input (not the -12dB) even if your bass is active. It only really crunches when the input signal peaks. Otherwise, it would be the ultimate affordable portable amp. In those conditions, it's a really good fuzz pedal, too!
On the other hand, with the OD and Fuzz you can use the Blend at 100% wet signal and still won't lose a lot of bottom end, which is a nice plus - as is the auxiliary input, for practicing.
The manual could be much better. For example, I am still not quite sure I understand what exactly the Saturate knob does - mostly, I just go as high as right before my tone starts to sound funny, for the compression. All in all, it takes some work to master all the dials.
I still haven't, but I would easily use it for recording of on stage (the option to use the DI pre or post EQ is also a great feature!). The metal housing and the foot switch feel they can take some stomping.
The other day I used it to practice guitar with headphones (7-stringer with a heavy distortion pedal) and it sounded pretty good, too! =D