There's obviously no actual answer to this, simply because it's so subjective, but I'd be interested in folks' opinions.
One person's "song from the heart" may well make another person gag, just as I've seen lengthy posts on Mudcat that often affect people in vastly different ways. I've seen many instances of folks "typing with tears in their eyes" after someones' words have reached them on a level that I just couldn't find.
So, my question would be: Do you cry easily? Do you get emotional over certain kinds of poetry? Conversely, what makes you say "that's so emotional it's cloying, or insincere, or just plain crap"? Is it strictly a "lyric" thing, or what you know about the composer's motives, or something else more intangible?
I'm not sure where I draw MY line, but it may be quicker than most, 'cause when I used to hear songs like "Watchin' Scotty Grow", "Feelings", "Tie a Yellow Ribbon" "Scarlett Ribbons" or "You Light Up My Life", I'd almost gag....and yet....they're ALL solidly constructed from a technical stand point, and obviously "reached" millions of folks. A friend once said "If you had kids, Rick, you wouldn't be as quick to dismiss songs because they were "too sentimental". He may have been right.