Have used through my solid state practice amp and my 50 watt tube head (jet ciry jca50 through marshall 4x12 90's compact cab)
Close to the boss sd-1, but not as good sounding in my opinion. It sounds decent , has more drive than i expected, but seems a little run of the mill sounding, and has less character than an SD-1, , but its a decent od, i could see many peeps getting exactly what they need out of it sound wise.
Its made pretty well, feels quite heavy, seems to have a buffer (not true bypass) preferred it using humbuckers rather than single coils, but good sounds on both with gain at noon, tone between 2 and 4 oclock
for the money its a great buy, maybe a better choice for peeps with solid state amps, than a classic tube screamer, but peeps with valve amps would be better off going for a ts clone, (EHX? Joyo?) or a boss sd-1, but solid state users will get this better i think, as its a bit more of an "amp in the box" sound, although it could be used well on both platforms, good budget option if you want overdrive end of the day.