So i've owned this piece of... sound, for a couple of years. At first of course it sounded like a guitar coming through a laptop in a PA, but now i think i've harrnessed the sound it was meant to have.
A while ago I did a speaker change for a Eminence Swamp Thing, just one in mono, and that really helped, despite the gritty nature of the speaker.
Next I followed the mod on this forum somwhere, to add a back panel to the flextone XL, and that really tightens up the low end to be barable. I'll post pics if i can find them.
Then of course, my guitar isn't the hottest thing around, but the way my pickups are setup right now, I got a sweet mix going.
Now the flextone, while i know I tweaked it with line edit a while ago (for mic and placement), the rest was just on the amp itself, my amp reads as follows.
yellow treadplate, PLEX45 cab
Reverb 10:00 largest room
tape echo delay at 10:00
now my guitar is actually enjoyable to play! but too bad it's the only good setting i have found.