Interesting, and your sonic description. The internal construction makes them next to indestructable, as they self protect (very suitable and usefull for high powered amps), but the by product was high impedance / low damping factor. I just wondered if this had changed with any new generation devices. This would also explain your comments on sound character as this is an attribute (or not  ) of valve / tube as well. It is a lack of precision when compared with the faster bi-polars. Attack / leading edge suffers and also mild overshoot can occur. This is more of a problem with fets than with valves as valves tend to distort evenly and fets tend to distort oddly, harmonic wise.

Think of me being locked away in an audio time warp for the last 6 - 7 years, I haven't even read a Hi-Fi mag in that time. I wouldn't have thought I would have missed too much of any importance though.

Richard