I have actually used the s100 in my DG 100 for 1 season. I popped for the AHRS as well. 80mm is the way to go.

I ordered the lx navigation Eros first and then returned it. I preferred the simplicity of the S100. I found the era to be slightly less user friendly but it’s basically the same unit.

You will be happy with the S100. It has all the bells and whistles and is easy to use. I have it on electronic compensation though and it creates an overly sensitive and optimistic vario. Adjusting internal settings has minimal effect on this. On the DG 100 I would use the traditional TE compensation. I think you need the combo probe to get good performance with electronic compensation on the S100. I find myself waiting on the winter to confirm a thermal before turning. The S100 is usually right about the thermal and quick to identify it, but screams like it’s going to be a 5 kt climb until you exuberantly turn and find it to only be 1.5 kts. Yes, I have tuned it for stick thermals Properly. The winter stays honest throughout. I think this is due to the location of the static holes...

The $800 AHRS option sure is cool eye candy and could come in useful on that wave day where it closes in below you but Otherwise, you won’t use it.

My last comment is that you have one option for tone. Yea you can adjust it slightly but it’s doesn’t change much. For $2,000 you should have 10 options for types of sounds for the vario. It blows my mind that nobody seems to care and it’s not even discussed in reviews. The tone should be highly adjustable just like the face of the vario. Instead you get a standard beep. Cambridge and Tasman had some nice option. The industry needs to pamper attention to this as we all have to listen to it for hours on end