Maven itself works fine. In nine years of Scala I've never understood what problem SBT is supposed to solve - it seems very complicated to no real benefit.
I loved the incremental compile/watch tests stuff myself. It's been a while, but I do miss having all my tests run every time I save a file.
But I do accept that sbt is not everybody's cup of tea.
I had heard that use case mentioned now that I think about it. To my mind it makes much more sense to have the IDE handle that part; the IDE knows which file I've edited and when I've saved it rather than having to scan the filesystem. But I guess some people must find it useful.