All that in a nutshell... back in the day of cartridges filled with poly-fill fiber and a bridged atomizer, some folks discovered that skipping the poly-fill and just dripping the juice directly onto the "Bridge" of the atomizer, the flavor and throat-hit was magnified.
Then somebody manufactured atomizers without the bridge, nice improvement. Now, just Google "RDA" and see where we are now. Pretty amazing how far this hobby has come in just the last couple years.