@arafiq thanks, I will try a good solid state amp with the 40.3 sooner or later. Maybe a Hegel. At the moment I run a full tube system with a Mcintosh c2600 tube preamp into various tube power amps.
The Harbeth matches nicely with the MC275 and the Music Reference RM-200 which is a hybrid solid-state/tube 100 wpc.
About the lossy cabinets, I thought that this is backed by scientific data from the BBC research. This type of construction allows the cabinet to dissipate energy in a way that produces a natural and uncolored sound, especially for voice reproduction.
Voice reproduction is one of the greatest strengths of Harbeths imo.