In search of best front-end workflow with gulp i found a benchmark test for CSS minifiers. I was previously using cssnano library and as a minificator it is good but there are some which perform more actions and can be a lot quicker.
So the ex gulp-minify-css and now gulp-clean-css which uses cleancss as a minifier has very strong results but what really made me change my mind and try cssclean was that it has ability to combine mediqueries. I had a lot of the same mediqueries when using sass mixins so that was great and i did not have to use one more plugin for that. Also the list of options is really great and with all of that its still in the fastests area.