Firstly, yes you correct that the EyeX SDK has now been replaced by Tobii Core SDK with all features carried
over into this new API.
Regarding cross compatibility with the various products:
Tobii Interaction & Stream Engine API both of which are components of the Core SDK will work natively on the Tobii EyeX & C4 Eye tracker.
Further detail of the Core SDK can be found online @ http://developer.tobii.com/tobii-core-sdk/
The Tobii Core SDK may also work with the Dynavox Range of eye trackers (PCEye Go, PCEye Mini, I12, I15, etc) however depending on the circumstance, this necessitates a special licence that can be obtained by contacting the Tobii SDK licencing team directly – [email protected]
If you have a more specific request for product hardware software compatibility please let me know.