Sariel has published his test of an early version of BuWizz. BuWizz is not the first system to replace LEGO PF ir remote control with a bluetooth solution, that allows you to control your creations from your phone. But unlike S-Brick that was getting popular recently, it also packs extremely efficient battery into one box.
So in a 4x8x3 studs box, size of Power Fucnction Rechargable Battery Box we get a more efficient battery, and 4 power connectors, that are equivalent of 2 IR towers, or one SBrick. That is a lot of saved space, especially if you try to build something compact.
According to Paweł, it is very responsive, and extremely accurate. There is also a high voltage mode, where battery is able to output a little bit higher voltage than PF standards, resulting in more speed and power of the motors. But remember, you are using it on your own risk, as it can influence your PF Motors lifespan.
To recharge the battery, you use microusb port, which makes it easy to refill the power on the go with any power bank.
BuWizz has a kickstarter campaign running now, where you can get it at $89 as an early bird, or $119 as regular supporter. You can of course pledge more if you wish for it to became reality.