I don't see where this would free up any HP except for if you're having valve float. Any energy required to compress the spring on one cylinder is offset by the spring being closed on another cylinder at the same time. No energy is lost by compressing a spring. It is simply stored, then released back into the system as the valve closes.
Now, if you have valve float, that means the spring can't close fast enough. If that's the case then the lifter isn't riding down the back side of the cam lobe in full contact. This prevents the energy from being returned to the cam shaft and thus back to the system as a whole.
If this really freed up HP, then adding higher pressure springs would take HP. Which, it doesn't.
Don't think I'm not kinda psyched about their idea though. I've had an idea for this for quite a while. Fairly similar to their implementation. The only thing I never figured out is how to assemble it when you put the cam into the engine. After that it would've worked just like this.
