Here's an idea that I've thought about (based on a recent 8ohm/4ohm cab thread)... Given that many heads now can comfortably run at 2ohms (iAmp800, EA350 and 650 and some of the Acoustic Image models), to get the ultimate large/medium/small room rig you could purchase a 4ohm 410 cab and an 8ohm 210 cab (for example an Epifani410UL at 4ohms and a 210UL at 8ohms). With the iAmp800, for example, for small gigs, the 210 at 8ohms would 'pull' about 500 watts from the amp and be a great sounding small rig. For moderate to large size gigs, the 4ohm 410 would pull 800 watts for from the amp and put out a lot of sound. For the largest of gigs, combining the 410 and 210 would result in 2.66 ohms (and here's the point I want to make sure I have right), the iAmp would put out about 900 watts or so, and each of the 6 10" speakers would draw the same wattage... resulting in a 'virtual' 2ohm (approximately) 610 cab. so, you would be optimizing the power of the amp and size of the rig to the three types of gigs with one amp and two cabinets. Is my math correct and does this make sense?