I'm driving my Eidolons Vision (which use same tweeter and midrange drivers as Opus) with a Lamm M1.2 Ref hybrids without any problems.
Having said that, I think ML1.1 amps are a better match than either of Lamm hybrids, since they sound fuller in the midrange, which in turn complements Avalons sound characteristics better.
I wouldn't worry too much about power - I have achived an OUTSTANDING success driving my Eidolons with 16W SET amp. In fact, it made me thinking about selling my Lamms and getting a SET amp.
Having said that, I think ML1.1 amps are a better match than either of Lamm hybrids, since they sound fuller in the midrange, which in turn complements Avalons sound characteristics better.
I wouldn't worry too much about power - I have achived an OUTSTANDING success driving my Eidolons with 16W SET amp. In fact, it made me thinking about selling my Lamms and getting a SET amp.