well i've had a good chance to play my gh50l in various situations, so i guess i can give a short review and a comparison vs. my other amp, the marshall vintage modern. the cool thing about this comparison is that they are both 'single channel' amps. and i put single channel in quotes because that's how they are marketed, although in reality, there are footswitchable gain stages or, in the case of the marshall, a high and low 'dynamic range'. dynamic range is really just clean and dirty, but i digress.
when i first got the gh50l, i took it home and fired it up at bedroom volumes. it amazingly sounded pretty decent. i only had the volume around 1.5, if even that. the tone is very dry, somewhat compressed and harmonically active. this is definitely a hard rock/metal amp. in comparison, the vintage/modern is more of a classic rock/rock amp. it does not sound nearly as good at low volumes (which is expected of most tube amps), is quite a bit brighter and more open and the bass is not as tight. after running through the laney for an hour or so, i was aching to crank it. band practice was the next day though.
in band practice, i hooked it up to all of my pedals (all 3 of them, lol). first thing i noticed is that this amp is loud for a 50 watter. the vintage modern is 50w as well and i can usually get it up to around 5 for practice. the gh50l was actually louder than the marshall at 3. maybe i'm hearing the natural difference in the eq's of the amps, i dunno. anyway, the laney of course sounded better when it was opened up volume-wise. it's very focused tone, very compressed. in fact, with my compressor on the same settings that i use with the marshall (tightens up the bass considerably), it did not sound significantly different. the gh50l also has high and low inputs, which the vm does not. cleans sound better overall on the vm (although they do sound decent on the gh50l, if you use the low input), but the gh50l's gain is more to my liking, at least for harder rock/metal. it's just less hairy. the compressor tames the hair down on the vm, but it's still a much more mellow sounding amp overall.
a couple of days later i gigged with laney and got it up to 5, lol. it was insane, but i loved the way it sounded. this amp has plenty of gain. if it wasn't for the fact that it wasn't a one channel amp and didn't have independent eq and volume control, i could probably eliminate my distortion pedal entirely. the gh50l is definitely a different beast than the marshall vm. more aggressive sounding, but i wouldn't call it better. just depends on the application and preference. one thing i can say, it's definitely one hell of a great value, especially used. no one knows about these amps. owning one is like being in a secret club, lol.