We used lift, we're in the process of ripping it out and replacing it with something else, anything else really. When I last checked a few month's ago, Lift's documentation is terrible given it's complexity. A project that is as large as Lift cannot be learned by scanning the source code and the number of examples out there to do something really custom is lacking. Tons of it's source files have only the slightest smidgen of Scaladoc if any at all.

Also anything that actually is documented is probably deprecated or about to be usurped by another feature. No classes should be added to lift without proper documentation added first. Yes it's open source, yes no one wants to write documentation at the end of the day it hurts the project however. I don't want one on one support or having to write to mailing lists I want a good explanation of what is going on top to bottom.

However I hear over and over it has worked wonders for other people, so YMMV. It's certainly not the only way to make a Webserver in Scala it just has the benefit of being one of the first big Scala projects, and it has used that time to bloat out and grab as many features as it can without documenting them properly.