This amp is either incredibly frustrating or incredibly rewarding, depending on your desires and your setup. This really isn't for everyone, and some guitars just don't seem to agree with it (I should note that this isn't a problem unique to this amp, as I had similar experiences with an Epiphone Valve Jr.)
If you have a humbucker equipped, dark sounding guitar, this is probably not the amp for you. I usually play a modded LP with a JB in the bridge and a humbucker sized SD P90 in the neck. The amp took to the neck pickup *relatively* well, but the bridge was all mud unless I dialed up the gain, turned down the volume, and cranked the tone full bright. After a few disappointing months, I swapped the bridge pickup for a P90, and it's like night and day. With single coils it SPARKLES, especially with the gain up to about 4 and the reverb around 7. A tele would be divine.
The build is solid and the features are actually pretty nice for a simple little tube amp. It would probably sound even better through a more substantial cab, but for my needs it's fine (now).