You bring up some great points. To address the first with tongue position. The generally high tongue position I'm talking about is further back even then the vowel forming part of the tongue. So for example, I can hold that back part of the tongue up, therefore focusing my air, and still create vowel sounds from ah-i (just the "oh" seems impossible). So there is still plenty of room for variation, but you are still constantly focusing and increasing the air speed. I hope that clears it up. Its really apparent in the comparison clips. I have no problem with the low notes and they even sound better with the "higher" tongue position. I very well could be making an "ah" vowel sound. I honestly would have to go experiment to be sure. Hopefully that explanation helps.
To address your articulation stuff. I think I'm going to have to disagree. Charlie Parker articulated many of his accents even during his fastest playing. He didn't articulate very much during those super fast lines, but he would still articulate key points. Its part of what makes his playing sound so clean and amazing. However, I was addressing a tempo where articulation is very possible, which you can hear in the sound clips.
Thanks for your comments Florian, especially the part on the vowels. I think that will help readers understand where I'm coming from. I almost want to do an edit in the article and include that information! By the way, the higher tongue position comes from Joe Allard. Its one of the concepts he taught (though I know he taught different things to different students). Anyways there is some great info and conception ideas at joeallard.org