Slinky looks very neat! I do feel it inhabits a very different niche from devd, though. I have no ambitions for devd to compete with tools like Grunt, Gulp or Slinky.

Devd has a simple job: it just serves files and triggers livereload when files change, and is completely agnostic about the build process. That means it works very well as a complement to Gulp - in fact, this is one of my primary use cases for devd. My gulp setups are simpler now: I've ditched Connect and node livereload libraries, and instead gulp JUST renders files to disk. It's early days, but having two sharp tools each doing what they do best seems to work well.

I should add that I definitely don't think there's one "right way" to do this stuff. I love the fact that we're free to explore variations to see what works and what doesn't. The more things we try the merrier!