I think I would reverse that...a tube amp will work better at the higher impedance than a lower one....not necessarily that high impedance works better with tube amps. In fact, many speakers can benefit from series resistance, as the solid state amps are often more linear at 8 or 16 rather than 4. I'm a fan of one driver per amp channel. That minimizes the interaction. I have heard some very good very linear small solid state amps. Many think tubes are warmer. I have both, some days I listen to one over the other. I'm not sure I am in the camp of one is superior. I CAN say since solid state tends to be cheaper there is a glut of cheap solid state amps. But the best against the best is pretty darn close. Many high end items are no better than the best mid level, or even the best cheap stuff. These days much of the high end is designed for looks and profit.