Mrtennis, I'm assuming you're referring to the "8A". Yes, in my review I describe the differences between the 8A and 8B in detail. I was able to conduct the listening tests in my room after changing the tweeter to upgrade it to the 8B. The change was permanent (technically reversable, but practically, would require resoldering the old tweeter in, etc.), so I was not able to switch back and forth repeatedly. However, I had extensive experience with the 8A and took notes prior to the change so that I could compare the differences I heard.
Mrtennis, I also agree with you that unless one has a truly refined higher end solid state amp, the 1.6 will have an edge/stridency in the treble which is neigh unto impossible to remove. CDP's will also have an effect on this, as will cables, but my conclusion is that virtually nothing will compeletely tame that aggressive treble - it is inherent in the design. Even the LFT-8A had a similar harshness, though not as pronounced, in the high end until the new tweeters were installed. Now, the intensity of the treble is much more comparable to a refined dynamic speaker, better integrated.
Nealhood, your feeling that the 1.6 is the best speaker in its class was also my opinion for many years, until I was able to conduct listening sessions with both speakers in my room using a variety of equipment (see my review). Your opinion is a popular one, but many planar fans dismiss the E.T.'s without justification and would be surprised at what they would hear from the E.T.'s.