I had to look up what this 'Cobra Coil' was, and I found an interesting video about from a fellow at Youtube.
CLICK HERE to see it.
I think if you already have an Iron CObra, this might be a very useful device with some very good pluses to pedal feel.
On the flipside, the biggest selling feature is that it is primarily gives a higher spring tension ability for the pedal. The effect means more downward energy from your leg to achieve a downstroke, but the benefit of returning the foot board to the starting position more quickly. The problem is that there is a disconnect between the footboard and the cam on the upstroke of the pedalboard. Moving the footboard upwards while the pedal is not being used will show that no energy can be returned upwards into the beater because the chain linkage prevents it. Only a direct drive pedal can do that.
If the selling points of this product interest you and you have not yet bought a pedal, I would give you the advice of considering a direct drive pedal.
Some options you may consider would be Axis, or Yamaha Flying Dragon, or Trick, or Pearl Demon Drive. Only a true direct drive will play like a direct drive.
Yes, they are different. Yes, some people don;t like to adapt to them because they are different, but those who really wanna get their feet moving most efficiently should have a look at them.
Now if you already have an Iron Cobra,, they do play excellently so this device does have a benefit and could be combined with the direct drive linkage another fellow here at DrummerWorld makes. I think if you bought an Iron Cobra in conjunction with the direct drive converter kit, you may well have a really interesting pedal. I'd certainly check one out at a store if it was made like that.