After listening to the 8Ts I bought from Mark (doro), I really began to scrutinize my single driver Cain & Cain Abbys. The Abbys have fantastic imaging, respectable bass, and mids out of this world. But, after listening to the same material on both the Abbys and 8Ts, it's pretty obvious the Abbys can't match the HF and LF extension.
So, I rigged-up a pair of super tweeters, rear-firing, with a simple external crossover on the Abbys. The SQ across the FR was so close to the 8Ts (with the exception of bass extension, so I added a small sub) you would swear they're the same enclosures. The 8Ts are ever so slightly less "open" than the Abbys -- but, I'm driving them with a 75 wpc, push-pull amp, versus 4 wpc (bridged mono blocks) SET amps. These are also, BTW, the absolute best sounding speakers I've ever driven with my Dynaco ST-70.
I guess what really amazes me is the single point source imaging effect coming from an enclosure with two drivers, a front-firing tweeter, and front-ported bass. Polk did this little speaker right! After all my experimenting, I laughed out loud at all the components and wiring I had to string together to get close to a match with these jewels.
If your using moderate powered tube amplification (35-75 wpc nominal), and looking for a speaker you can listen to and enjoy for hours on end, this is the ticket IMO.