The company Sixense, out of silicon valley has been known to be one of the leading pioneers in the quest to improve the user interface that we use to game and interact with our computers. They first introduced the Hydra and eventually Razer picked it up and made it their own. The experience with the Hydra was interesting and presented a new way of playing certain Steam games. However, it's use was limited in scope and was eventually broadened with the integration of certain VR technologies, namely the introduction of the Oculus Rift which changes the way we see things in our computer but still doesn't change how we interact.
In order to improve the experience and immersiveness of the motion controller experience, the guys at Sixense have been developing the STEM system which incorporates multiple motion controllers and sensors to create an immersive and responsive experience. The guys over at Sixense decided that they would crowdfund this effort instead of trying to fund it with their own R&D funds or getting VC or angel funding to support the effort. So, while these guys are providing us with what could potentially be one of the best motion controller systems out there, we haven't had a chance to try it out or anything like that.
The good thing about this upcoming controller is that they have already funded the project within HOURS of being on Kickstarter and they are very serious about taking user feedback about the system. It will already be open source and will likely entice many PC game developers to include whatever API it utilizes into their games in order to enable such a controller within their game. As an FPS gamer, I think it would be interesting to see how it would play something like Battlefield 4 or CS:GO and knowing Sixense's cooperation with Valve in the past, I have a feeling we'll see current and future Valve titles supported.
The lowest current price that one of these can be obtained over at Kickstarter.com is for $149 and then you get to pay more for more benefits. They also have a pretty good promotional video that you can check out that brings all of the proponents of Virtual Reality and some other successful VR Kickstarter projects like Oculus VR and Virtuix Omni just to name a few.