Hmm.
I'm also a faithful user of the Vox Pathfinder 15R... the Bass and Treble knobs are very interactive and I can get very nice sounds even at low volume. At high volumes, depending on the room it can get rather harsh, considering that the stock speaker is only 8 inches wide.
However that said, I use a 10-band EQ pedal to tighten up the bottom end and clear out the mid-range. If you wish to buy that amp, I would advise you to do likewise.
Another tip: try tilting the amp backwards against a wall such that it faces your gut, not your shins...
My pathfinder settings:
Gain 9 o'clock
Volume 11 o'clock
Treble 2 o'clock
Bass 5 o'clock
Reverb 12 o'clock
I seldom if never use the tremolo, so I tend to have those controls all at zero.
*shamless plug: planning to purchase a BIG amp soon, so if there are any interested parties kindly PM me your offer for this amp.