Thanks for your answers. I will try to exchange the Efnote snare for the ATV snare.
Nonetheless, it certainly makes sense for the eDrumin modules to support the Efnote products because at the moment I think Efnote overtakes ATV ...
What do you think about my theory?

I bought the Efnote 14" Snare now and I'm very happy.
But positional sensing doesn't work right I think.
@Rob: will there be a preset or tips to get a pad with 4 sensors work right?

At the moment I'm looking for a new main snare.
I would prefer the EFNOTE snare (EFD-S1250-WS OR EFD-S1455-BO) or the ATV snare (aD-S13). Which one is more compatible to all the features of eDRUMin 10?

I have no experoence with the PD-125 from Roland but I play the drum-tec pro custom snare drum with an ED10 and I can tell you that it works just fine.