interesting toy, but still a toy. after watching YT reviews and reading praises for this gadget, must say that I'm kind of disappointed.
it is usable for playing something which is not hard rock or metal. even some effects like delay and reverb are pretty good. but high gain distortion, or harder overdrive are far away from decent sound, at least for my taste. there is too much fuzziness in those types of sound, no "bite" at all, too much muddiness. and too much bass that is impossible to reduce.
it is practical toy, light years ahead of certain gadgets that I used in the past like Vox Amplug2. not as good as Boss Katana GO which I tried few months ago, at least regarding built-in options. that Katana GO also wasn't so good in high-gain territory.
however, Fender Mustang Micro Plus is practical for recording, and less annoying when played through mix, because then you can not hear all its "weakness".
I used it with T.Bone 815 over-ear studio headphones that are sold in bundle with this gadget, also with my Sony on-ear headphones, and with Panasonic PMX-90 mini HiFi, but wasn't happy with sound in any of those. sound is too much artificial and plastic for my taste.
if price for this gadget would be 50 euros max, then it would be less disappointing, but 130 euros is too much in my opinion. I'm not felling bad for buying it, but not feel happy either.