I've had the 927 Be pair running in at home for about 50-60 hours over a three week period. (Would've been more time, but my wife made me go to the lake and close up the cottage on the long weekend.)
I'm in love, but still getting to know the new paramours. They have definitely improved over the warm-up period; a bit of high treble glare has mellowed nicely. I started them off with the Musical Fidelity 3.2CR power amp and the MF 308 pre-amp. I thought they sounded wonderful, until I hooked up my new Musical Fidelity kW 500 Integrated. This amp took the speakers to a whole new level. It added power and punch to the bass, with much greater articulation of individual bass notes. The bass is more than sufficient and satisfying for my small room; 12' x 15'.
The highs gained more of that laser-like detail in the beryllium tweeter; more air around all voices and instruments, with transparency more typical of good electrostats. The soundstage has a hugeness, the music has a sheer presence that wasn't there before; like a charismatic person that fills a room, even when quiet. The range and palette of musical sound is expanded in all dimensions, without sacrificing the middle.
Am I eulogizing the speakers or the amp? Well, their synergy of course. These speakers do take time, and they do reflect the quality of source and amplification.
A couple of responses to Mr. Gabriel's observations above, if I may, and with respect. I agree heartily that the regular (non- beryllium)Electra 926 was and is an exceptional bargain. I feel the same way about the Electra 906, which I owned and thoroughly enjoyed for about a year before this upgrade. Upgrades from that level are going to cost significant coin for lovely, appreciable, but proportionately modest gains. You are not going to double your music for about twice the money. Forgive me if that is trite; I don't mean to sound patronizing.
To me, upgrading from the 906 to the 927 Be did all I asked and more. It took everything I enjoyed about the Electra 906 sound, added a greatly enriched bottom end, suitable to a small room context (these are only 6 inch drivers after all), and added considerably to the already fine detail in the highs.
I wouldn't have sought 'massive bass' in this speaker line, respecting that this may mean different things to different people in the context of their system, environment, and preferred music. That said, bass weight will increase proportionately if you check out the bigger 937 Be with its pair of 8 inch woofers, or the Utopia Diva with the side-mounted version. Lots more money again, and heavy competition in the $5000-$10,000 bracket, on up. Or, going back to the 'regular' Electra 936 might be more satisfying, and affordable, if there is an appetite for more bass. To me though, the JMLab sound is typified more by well-mannered and balanced bass than by sheer mass.
If I can get away with one final cliche, as with many high-end products, fine wines and beautifully finished woods, these speakers promise to age well. But reliable evidence of long-term performance is hard to come by when you are making choices. That's one of the values of a forum like this of course, where you can hear about well established track records. But with a new product, you have to extrapolate from the known quantities, or wait for history to unfold. Enjoy!