For example, Lisp has a simple syntax, but most people would consider infix math notation easier, although more complex.
The main downside of Groovy is: it's not as fast. And of course the programming paradigm is less revolutionary and more pragmatic, though that could also be a big upside.
In fact Kotlin looks mostly like Java with some additions to make everyone's lives easier (closures, extension methods, data classes).
The groups I worked with made different determinations than your team, but if you guys love it, enjoy. Seriously, if you find a technology your whole team loves, you are KILLING it.
Both companies I worked with have since dropped Scala (after literally hundreds of thousands of dollars spent on the attempts) entirely internally due to maintenance and talent acquisition issues.
In my experience very little Scala code uses DSLs. Learning Scala isn't that tricky for anyone who knows Java, which is a pretty big pool.
Edit: It was two years ago so other than Lift and some SQL DSL I don't recall which libraries we were using. I do recall wishing I hadn't taken that job.
I too suffered a bit from DSL hell, especially some of the more extreme examples like the library "dispatch" where you need a "element lookup table" to figure out which squiggly line to use. But once you have a stable set of dependencies the initial DSL influx subsides and you start to work with a fairly manageable subset of them on a day to day basis.
Hundreds of thousands of dollars is on the order of, what, 1 engineer-year?
