I don't know if I'd call the E3 plug decent. My reasoning is pretty solid. Current will take the path of least resistance every time. The ignition system on these little motors is not much, so don't expect very high voltage. Automotive ignition systems run at about 15-20ish Kv, so pretty high. So if the voltage coming from this cdi is as low as it is, it's not going to make another arc. Even cars don't produce 2 arcs when using dual tip plugs. We're not talking about lightning bolt voltage here, so don't expect arc branches at that low of a gap and voltage.
Many parts stores will try selling the gimmick plugs. Words like platinum, iridium, +2, +3, +4, etc. The fact is that automotive ignition is actually fairly sensitive to the type of plug you use. You can't upgrade the spark plugs and gain anything. The spark plugs are chosen with the ignition system in mind. If you go from a copper spark plug (oem) to platinum, its resistance is a lot less. Most people think that means less drag and more power. They're then going to think that it makes more power until the car starts driving weird. What's happened is that the secondary side imedance went down. The reflected impedance across the coil is less, so whatever driver runs the primary side (solid state ignitor, points, etc) has less resistance as well. This means the current going through the primary side has gone up, and will burn out soon. This is fact, not opinion.
Some manufacturers do use platinum or iridium plugs, but their respective ignition systems are built with current limiters so they don't burn out their ignitor and coils.
I remember a while back there were these split-fire plugs. Another gimmick plug, and they're no longer sold because they got sued!
I definitely consider the E3 as a gimmick plug. The dual tips will not give you more spark. Look closely to the top picture and you can see accelerated wear on one side of the electrode. As it burned only on the corner, it eroded the plug a lot more than normal. That's after 20ish miles, by the way. Maybe it somehow does burn hotter (which is possible) but it won't do that for long.
Also, there's a reason OEM manufacturers stick with single tip plugs.