The Vpower works like the splitfire. Two spark paths for a slightly more efficient burn. I've been running them in all my cars for about 5 years now.
I ended up going another heatrange colder, as I was burning the TR55'* up twice as fast as I should have. NGK suggested to me that I step down to the TR6.
Ya, I've been running with splitfires in my Bird and Jeep for over 10 years and wouldn't switch..........but these newer engines seem to command a much more premium plug. If from only the standpoint of not having to slice hands trying to get at the rear ones. A standard electrode, like the v-notch type, should be expected to wear faster than a higher priced iridium plug.
I would have expected that you would be running with a higher end plug.
The factory plugs cost $15. cdn each and the other iridium type cost about the same.
The Vpower plugs must be far less expensive.