I picked up an Ibanez Promethean P500H from ebay recently. I'm impressed how small it is, yet it feels substantial. Lots of different tones, thanks to the "Vibe" control and EQ. This is going up against my Tubeworks RT-3300, and I'm using an Acme B2 series II @ 4 ohms. Well, the Acme is definitely happier with more wattage (260 watts vs 500 watts). The rest of the band like the added clarity of the P500H. But the Tubeworks just has "something" about it, and I can't help but wondering if the real issue is the Acme. You see, I used to run the Tubeworks into a Carvin RL6815, and that was one of my favorite tones, but it just wasn't portable. So now I'm guessing whether I can choose between heads if I'm not certain about the cabinet. Thoughts about running either of these heads with a good 15" cab, like maybe a GB Focus? Can't find 'em local.