The company Manus ( a KickStarter campaign ) are about to release their VR haptic gloves. From what I've seen to date these are the best possible solution to hand tracking.
The Leap Motion relies on an optic system (camera based) so it suffers from a limited operational space so if you were to throw a hand grenade or ball once your hands go out of view the system would loose track of your hand / finger position.
Percpetion Neuron has a better solution using IMU sensors but IMU's are sensitive to electrometinetic fields, so need to be kept well away from any electrical device eg. a computer screen or they loose their ability to accuratly track.
So now we have the Manus VR glove that utilises flexible sensor strips... these I feel are far more accurate, don't require camera or IMUs.
Once HTC release the lighthouse API Manus will intergrate the tracking system into their glove aleviating having to strap the VIVe controller to your fore-arm.
as a Control vr backer, I say don't back this unless they actually have a prototype and aren't trying to pawn off some $30,000 glove that someone else made as their prototype. This wouldn't be the first scam like this if it is one