Should I use GulpJS or Ember-cli?

I am in doubt. Always used the Gulp to minify, concat, etc. But am in doubt whether to use the Ember-cli or continue using Gulp. For example, with Gulp I can use http://cssnext.io/ and that helps me in the projects.

Or I can use Ember-cli and GulpJS together? Then use the Ember-cli on the basic tasks that it already does and Gulp for more complex tasks?

Ty