Yes, I've heard them and owned others in the line.
They are the top line model in a lineup (L1,L3L5,L7) that was a reworking of the classic and very well regarded L-60-L80-L100 lineup with a narrow baffle, among the best sounding of the classic JBL consumer lines.
They used updated versions of those earlier bulletproof drivers. The 4 way L7 needed a large room to sound balanced, many thought the 4 way L5 fit better in medium rooms.
Very flat response, quite clean and somewhat monitor like. Certainly not up to the better audiophile speakers in imaging and soundstaging, but they will rock out very loudly and enjoyably.
They sell cheaply used, as do the earlier L80 and L100 models, but they are a quite nice speaker in a proper space and with a good front end.