The biggest price difference between the 805 and PM1 is because the 805 has the diamond tweeter. The PM1 tweeter is very similar except it uses a carbon fiber damped aluminum dome instead. The fiber damping has a significant effect on the behavior or a metal dome. I have several Mirage speakers which all use a titanium dome tweeter, but it's damped by a cloth surround. It's a sweet seductive tweeter with air and detail, but no harshness or ringing.
Having a more conventional but well-executed tweeter dome saves a lot of money, freeing up the cash for a good subwoofer (or two). The demo I heard was put on by B&W, so they were keen to show off how good the PM1 is. I was very impressed. It had much of the speed and transparency of the Wilson Alexandria XLF, though of course not the dynamic range or scale. But it had that core transparency and ability to draw listeners into the music that is so essential.
Having a more conventional but well-executed tweeter dome saves a lot of money, freeing up the cash for a good subwoofer (or two). The demo I heard was put on by B&W, so they were keen to show off how good the PM1 is. I was very impressed. It had much of the speed and transparency of the Wilson Alexandria XLF, though of course not the dynamic range or scale. But it had that core transparency and ability to draw listeners into the music that is so essential.