Well, lets look at that neutral current for a moment....
For a simple two-wire circuit, the only way the neutral can be "hot" is if the current has passed through a load. If the load is a simple resistance (like a light bulb), then you're going to feel reduced voltage, at 60 hz.
If it's a load that has capacitors in it (like a fluo ballast), those caps are going to give you an extra "kick." Sort of a "mini-stun gun."
For multiwire circuits, the current on the shared neutral will be combined. As I see it, the voltages will both add to each other, and merge .... meaning that the voltage will approach 208, and the current waveform will begin to look more like a "DC" line than a sine wave. This means a bigger contraction in your muscles- and a greater chance of not being able to let go.
The 'advantage' here to a shared neutral is that the loads are also exposed to the higher voltage ... so they might fry before you do! I wouldn't count on it, though.
