There is only so much you can do to the spark plug. And they are only a cog in the system that makes an engine work. Significant power gains will not be encountered by spark plug design.
They are not bad plugs, they are just not as great as they are made out to be. But then again, that's with like 99% of the aftermarket automotive products out there anyways.
I say...you can't lose, but you don't really gain either. Same with any other spark plug. Whether these are worth the price premium is up to you to decide.
I personally have used the Bosch IR Fusion (currently use), Bosch Platinum +2 and +4, NGK Iridium and Platinum, and Denso Iridium Power and Platinum spark plugs. All perform excellent in my cars I have installed them in. No noticeable difference in terms of power or fuel economy really. But they do come with a load of marketing. haha