The asset module is interesting even though I have yet to make it do exactly what I'd like.Currently I want to use it to make my personal website. The idea came from one of the article in the arachne website, where the writer spoke about using the asset module to build a static website generator.
My approach is to use arachne as a compiler for my assets. Everything is in my src and resources folder but these assets should not be used directly when serving the pages. I want to use the pipeline to compile and setup everything in another folder that I could then push directly to github pages for instance.
One thing I do is use the figwheel module when working on my pages to auto reload my css. The thing is I haven't yet found a way to use an output-dir as an input-dir for figwheel. Right now when working at the repl I use one arachne runtime to put the asset pipeline into motion and another to start figwheel which is a bit clunky.
Also one thing to look out for when working with the module is not to have an output-dir inside another output-dir. basically something like this:
(a/id :website.assets/html (aa/input-dir "resources/website/html"))
(a/id :website.assets/css (aa/input-dir "resources/website/css"))
(a/id :website.assets/website (aa/output-dir "target/website/"))
(a/id :website.assets/css-output (aa/output-dir "target/website/css"))
In this example you might have either only the html in the end result or only the css.
So to answer your question, with all this context, I like the asset module, it can solve problems very declaratively and the transducer functionality allows to process files with full clojure capabilities. For instance I use a clojure parser for .md files that returns enlive data that I then manipulate with enlive to add sections and divs where I need. Also the general html of my pages is an enlive template in which I inject my processed markdown. I find it very practical and cool.
The module seems to impose some constrains though, namely the fact that your output-dir have to match your input-dir in shape when I would have liked to be able to shape my output independently of the input.
In the end take my observations with a grain of salt, arachne is still in alpha, I am by no means an expert of what's already there and the documentation isn't finished yet. So I have surely missed some capabilities of the module and it is very probable that with a bit more examination of the source code and the tests I might find clean solutions to my problems.
Hope this helps and isn't to dry a read...