The flower-top 'flat-top' pins melt too, just like the ball ones. And they are supposed to be whoopie-do best-in-class from LQS. Some of my LQS pins, right out of the package, looked a little tarnished in spots. And they definitely don't go through the fabric as easily as the glass-head pins which are my favorite.
The glass-heads are nice and long, they don't melt, they are slightly narrower in diameter than the flower-heads and very sharp and smooth. Straight from Joanns.