All good questions...
The Toshiba datasheet "characterizes" that device at 100W PEP. That's a
conservative level, and it doesn't mean the output is limited to that
figure. My ratings are given at the 1dB compression point. That point
is kind of a standard in RF amplifier circles as a point where
lineararity degrades to an unacceptable level. The link states that the
"approximate efficiency" of an AB biasing scheme amplifier is 45%. That
number certainly has some latitude based on the level of bias and is
highly dependent on the quality of impedance matching. The 45% is based
on typical products available to you out there. As for Texas Star...
they have a pretty good product in the amp arena. Since they mass
produce, they can certainly offer their product at a lower price.
However, the quality of their components and overall workmanship is
often not optimum. The SkyWave design has some features that others
don't offer. These may not be obvious but for those operators who are
concerned about low harmonic content and high reliability... these
features sure help. Agreed, the SkyWave is not for everyone... and
hasn't been designed as such. I'm glad to see that you have taken
interest in this topic. Hope that helps.

Professor
www.telstar-electronics.com