Bruce there is some info from other users concerning this. Look in the archives under Decapo, the threads are quite recent. The concensus seems to be that the BE tweeter is a big improvement. I couldn't tell you since I have the latest Decapo with the acoustic lens with BE tweeter and the Nextel finish and have never heard any of the prior models. The BE model is just superb. These are among the very best speakers I've heard regardless of price in communicating the musical message without ever bringing attention to anything they're doing. Very natural highs, choral music is an absolute joy on well recorded music. The closest thing I've heard to Quad ESLs in natural tonality and coherence from a dynamic speaker with the added benefit of excellent dynamic contrasts of the music. Great extension without any hint of brightness or edge.