audiopile had some real good points, especially about the class A amps. I have a little 45 watt guitar that indeed walks all over larger A/B amps and is suitable for cooking food with. Ditto for the sound improvement over time though i switch from the stock EL84s to Phillips Miniwatts with very positive improvements in tone and a shorter warm up period.
Now to your original issue.. I have a pair of Dunlavy Athenas and i do not think they are very hard to drive at all, especially compared with speakers like Aerial. I'm using tubes, and have heard them with Pass labs ss amps and the bass looses almost nothing with the tubes while gaining hugely in the mids. Find yourself some amps you like and try them out from a listening perspective rather than getting bogged down in the math.
Now to your original issue.. I have a pair of Dunlavy Athenas and i do not think they are very hard to drive at all, especially compared with speakers like Aerial. I'm using tubes, and have heard them with Pass labs ss amps and the bass looses almost nothing with the tubes while gaining hugely in the mids. Find yourself some amps you like and try them out from a listening perspective rather than getting bogged down in the math.