OK, let me rephrase:
The best tube distortion happens past 3 o'clock on the master volume.
The whole reason I bought a tube amp is because of the smooth, punchy distortion that it gets when I crank it way up. If I didn't like my amp's distortion, then it would be completely useless to me and I'd replace it with an amp whose distortion I did like.
Sorry, not trying to convince you to hock your amp, but just keep in mind that there are some AWESOME sounding tube amps out there that no pedal in the world will ever touch in terms of distorted tone.
Also, no pedal will make a bad amp sound good. Not that you own a bad amp, but if you don't like its distortion, maybe its time to explore some different amp options.
Maybe try the half stack with some sort of power soak like a Hot Plate or YellowJackets so that you can really drive those power tubes (which is where the smooth distortion comes from) and keep the preamp distortion down (that's where the grainy "presence" comes from). That's why I suggested a lower wattage amp, because you can push those power tubes to the max and not make your ears bleed in the process.
Good luck, whichever route you end up going.