When comparing cssnext vs Pleeease, the Slant community recommends cssnext for most people. In the question“What are the best CSS preprocessors/postprocessors?” cssnext is ranked 5th while Pleeease is ranked 12th. The most important reason people chose cssnext is:
cssnext is a PostCSS plugin, which makes it pretty easy to use for people who are already using PostCSS.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Built on PostCSS
cssnext is a PostCSS plugin, which makes it pretty easy to use for people who are already using PostCSS.
Pro JavaScript-based
Because the parser/compiler can function in a web browser, it can be used with systems that cannot run similar technology on the server. For example, you could build a WordPress plugin with a front-end application that transforms CSS.
Pro No need to learn a new syntax
Since css-next only adds new CSS features in a way that all browsers can support it, it's still CSS. So there's no need to learn any new syntax.
Pro All-in-one post processor
preprocess CSS (experimental)
adds prefixes, based on Autoprefixer
provides fallbacks for rem unit, CSS3 pseudo-elements notation
adds opacity filter for IE8
converts CSS shorthand filters to SVG equivalent
packs same media-query in one @media rule
inlines @import styles
minifies the result
generates sourcemaps from pre- to postprocessors
Pro Combines media queries into single rules
If you have repeated media queries in your stylesheet, Pleeease will pack them into a single media query when compiled.
Pro Rem fallback
Rem unites are not supported in IE8 and below, so Pleeease provides a pixel fallback.
Pro Uses Autoprefixer
Pleeease uses Autoprefixer to add vendor prefixes based on which browsers you want to support (prefixes are added based on information from caniuse.com.
Cons
Con Lack of support in IDEs
Currently there is very little support for syntax highlighting when writing PostCSS plugins.
Con Not very popular
Pleeease is not very popular. This may make finding guides, tutorials or resources outside the official ones difficult.