Rebbi's small complaint was that the DeCapo did not capture the lower octave on stuff with Synth bass with his 300B.Rob, more precisely the complaint was that the amp clips when reproducing that and other material having high volume content at deep bass frequencies. Clipping, in turn, results in distortion of ALL frequencies that may be simultaneously present, including harmonics and other frequency components produced by the synth at much higher frequencies, as well as notes that may be simultaneously produced by other instruments or singers.
Resolving that problem while continuing to use the Kit 1 amp calls for a speaker having considerably greater efficiency than the De Capo provides. How well and to what degree the speaker can reproduce deep bass frequencies is a separate question.
Although the Klipsch's 99 db/1W/1m efficiency rating is arguably somewhat optimistic, as is pointed out in the review, it is undoubtedly MUCH more efficient than the De Capo.
My comment should not be interpreted, however, as advocacy for the Klipsch.
Best regards,
-- Al