i'm loving sbt, but still on projects above > 100 dependencies it gets really really slow to download it, while with gradle (even i dislike it) it is way way faster.
This is probably SBT's greatest weakness and Gradle's biggest strength, relatively. I've never run in to this personally, probably because I'm use Nexus[1] as a repository cache. My understanding is that the underlying problem is a limitation of the dependency resolution library they use, Ivy[2]. Gradle used to use this but at some point wrote their own dependency resolution library. There are some improvements in recent versions of SBT but you have do a little configuration. See here[3] for more details.
I also thought of introducing Nexus, but since we are only 3 Devlopers (yet, we searching though) it didn't too much sense. I also I hoped for Nexus 3 (but since I'm waiting over half a year now, we might introduce Nexus 2).
Oh and we also using the Cache, when working on newer sbt projects.
[1] http://www.sonatype.com/nexus/product-overview
[2] http://ant.apache.org/ivy/
[3] https://www.typesafe.com/blog/improved-dependency-management...