The big difference is that the PCEye Go eye tracker is a supported product based on an eye tracking platform that is manufactured in small quantities and with components that are still too expensive. The EyeX Controller is part of a developer kit, there is no support included (except on developer.tobii.com) and all components are ordered in higher volumes. We have worked really hard on the production and hardware sourcing side to lower the cost of each manufactured eye tracker.
In addition, a lot of work had to be done on the firmware/algo/hardware side to be able to maximize the performance of the new hardware platform, to be able to maintain the same level of tracking robustness across different faces/eye types and maintain robust tracking precision across the head movement box. I cannot share any details on this either, but there are some really awesome developers who made this possible.
Since the EyeX Controller is still in the final stages of development, we haven’t performed the full suite of accuracy/precision/robustness tests yet. When we get closer to the shipping date, we will be able to share more info on the hardware specs.