The first step in considering how to better integrate Scala and Java XML processing is a Google search to find the prior art.
That found the following
gem. The scala.xml.Elem is
prettyprinted to a String and then parsed into a DOM for processing by the Java xpath implementation.
This code illustrates a common concern with tools that hide the implementation details; they often hide significant performance problems. It might be argued that Scala implicit conversions will make this anti-pattern a common occurrence.