Have been flying with S80 + Nano3 + Oudie for two seasons.

My opinion is that the map feature on the S80 is to small and un-detailed. it can be used as a backup for Start Line/TP/FL and Airspace. But the Oudie is superior in this case.
I mainly use the navboxes screen in S80 and those are really good in combination with the vario which is also good. Since some FW upgrade ago has the wind calculation improved. There is no longer a need to thermal to calculate the wind and this is without the compass module.

I vould say that S80 + nano3 + Oudie (or XC soar) is a good and affordable system compared to the more expensive fully integrated system.

The S100 is the same HW and FW as the S80 + built in logger and battery.