I used faderport with samplitude, it was great.
I hope you'll make the driver for faderport 8 for Samplitude Pro X3 suite asap !!!
Magix is going to provide their own implementation, just as they did for the original FaderPort. Please contact Magix support for more information.
If you want to create your own implementation, the full MIDI Spec is published in the User Guide.
There is no driver for the profiles for each DAW. The FaderPort 8 is a class compliant MIDI over USB device. The templates for device control are contained within the application themselves. If you want to use the FaderPort 8 today, you can do so with Samplitude (or any other DAW) using Mackie Control or HUI Mode by setting the device in the on-board setup menu. Read the FaderPort 8 user guide on how to set the device for one of these modes. Then read your DAW user manual on how to connect Mackie Control or HUI mode devices.