Larry, I agree with you, and may add that what you wrote is especially true for the Tyros; I have recently tried a few styles from styles-music.de; they were labeled as "Tyros styles", but this is only partly true: they were styles originally done for the 9000 and then adapted to the Tyros. None of them used the megavoices and -overall- they were nothing special.
I think that the only way to develop good styles for a keyboard like the Tyros is to use the "morph" function and pick up tracks from the original Yamaha styles, to build up your owns (I think that Terry is doing something along these lines).
Re. styles-music.de, I think that in the past they used to hire professional musicians who were able to lay down some really cool tracks (personally I have learned a lot from their midifiles, both in terms of harmony and improvisation). Right now, it looks like they cannot afford to hire such good musicians anymore and their latest styles and midifiles are rather disappointing (I know that Roy André will disagree with me here... )