What can I say about them? Well, I couldn't imagine being without them. Everything else I hear seems slow or colored or hard sounding as in the case of compression driver horns. One day I will replace my PM4As with AERs but until then I could not be happier. I built or modified a variety of speakers before arriving here and I have no inclination to change much. I have had no inclination to change since I got them two and a half years ago.
The bass cabinets are Scala knock offs built with K33E drivers which were Damar varnished before Bert came up with the wood glue mod. This caused them to take a long time to break in but I like their sound very much now. The extened/ported back chamber brings them down to 40hz and makes them a bit "more" linear. The ports are 4x7", anything longer than that slowed things down way too much. I have them bi-amplified with almost identical 6S45 Differential, Push Pull, Single Stage, Parallel Feed, amps of my own design cranking out maybe 3 watts each. The color I picked was VW Beetle yellow which was dulled with an anti gloss additive for a softer, lighter look.
Don't worry Bert, I close the heavy curtains for critical listening!