Funny, I've been thinking about this a lot lately (I can hear Caroluna laughing already ....)
I don't know about the "heart", but I think it's definitely a vital organ, esp. for certain styles of playing. Some of the more "internally rhythmic" things like flings and the big "chugga-chugga" tunes seem to really come alive with a good combination of pulse and glottal articulation; it's more percussive and foot-stomping.
And then there are some tighter lighter tunes and settings, and treatments thereof seem to benefit from the more delicate approach of tonguing.
But basically, I think it's good to be able to do both, often within the same tune. It's whatever the passage, style, and setting demand in terms of emphasis (or lack thereof).
And now The Long Version .... (complete with bonus maunderings!)
I've asked several serious players about it over the last few years, and while the general bias one way or another seems to be personal, I think most good players can deploy both as needed. Louise Mulcahy told me she uses tonguing when playing the whistle -- makes sense, the crispness is appropriate, esp. to her style -- but tends to use the glottal approach on the flute -- again, that aligns with her style. Then, I listen to someone like Dave Sheridan or Paul Smyth, who seem to have a more crisp approach (And then there's Harry ... well Harry's a genius who seems to be able to do both simultaneously!) overall, and it seems tonguing's a little more prevalent in their playing.
After using glottals almost exclusively over the last year or so, I'm now trying more tongued articulation as well. (At first I stayed away from it entirely because I was warned that my tonguing was one of the things that would show me up as a classical player almost as fast as diaphragm vibrato ....)
FWIW, I've run into Rob's vocalization issue as well -- and once my larynx starts buzzing, it's hard to stop. (My classical teachers would have COWS!)
Anyway, bottom line I go back to the classic John Skelton "horses for courses" philosophy. I'm trying to learn to use both, because it seems like there's a place for each -- it just depends on what you're trying to convey and what serves the tune best.
'Cos there are times when a nice feathery "dah" or crisp "tah" is just more appropriate than a "gah", yah knah?
Deja Fu: The sense that somewhere, somehow, you've been kicked in the head exactly like this before.