not being a impulse guru (only installed it yesterday) I would say "jein" (knowing that you are german :P).
you can buy stuff via impulse but will be also their multiplayer client (which intends to use advanced NAT negotiation to reduce connection issues which is great news), doesn't use annoying DRM methods and allows you to manage games/applications you didn't buy via impulse (and if they cooperate with stardock you can even install/patch software you didn't buy via impulse originally.
There will be a Matchmaking and Ranking service for upcoming games (and I hope a tournament system (Ideally both Elimination and Swiss system - I am allowed to have dreams :P))
There are also lots of already implemented or upcoming community features.
In the end it is still similar to steam but I already prefer that early incarnation alot over steam (which I don't like at all)... you might check out the review of Stardocks CEO (which is quite neutral for being so biased actually^^) @ https://forums.sinsofasolarempire.com/315154.
for battle.net users it is a change to have a external mp client for sure but there are several advantages as well as some disadvantages for it. just give it a try