I am in the process of switching from log4j to Logback. One of the key reasons for doing that is the availability of SiftingAppenders in Logback. Your website promotes Groovy as being the more intuitive, consistent and a shorter syntax way of configuring Logback, but then goes on to say SiftingAppenders are not supported in Groovy. That is a big turn off for me and a quick search on the Internet confirms I am not alone. It feels to me this feature should be added.