I've used Brunch before, it was very good at compiling assets. However at some point I needed to run tests and compile within one command, and this was the time I've migrated to Gulp. To be honest Gulp feels more developed with the richer ecosystem of plugins. I haven't noticed much speed difference Gulp vs. Brunch.
@nikitakorotaev Gulp / Brunch have different use cases. Brunch's main point is simplicity which of course limits number of features it has. For most fronted apps brunch worked great in my experience though.
Waffle
Brunch
Mute.vc