Like you, the only instance I've heard of in with Outlaw amps have had problems driving Axioms was when they were in a tremendously large room (8,000 cu.ft. is off the charts big). There have been folks using the 200W Outlaw amps with Polk LSi towers (which are low impedance and low efficiency) with good results. There have also been a whole lot of people using Outlaw amps with various Axiom speakers over the last decade.