Sagem and Garmin and their was no comparison in my book.
Also worth considering the prospects for ongoing support and enhancements. The Garmin G500H is a close relative of the G500/G600, G1000, etc, which are widely deployed in many acft. This bodes well for ongoing feature development and technical support. The Sagem seems to be much less accepted in the marketplace and could wind up an orphan in short order as Garmin eats their lunch. I have a G500H in a new B407 and it is quite nice. I actually prefer the Chelton Flight Logic system overall, but this was twice the price and is at or near the end of its technology lifecycle, with unhappy implications for future enhancements and support.