There are two reasons I can think of not to use Groovy (or Jython, or JRuby):
- If you really, truly need performance
- If you will miss static type checking
Those are both big ifs. Performance is probably less of a factor in most apps than people think, and static type checking is a religious issue. That said, one strength of all of these languages is their ability to mix and match with native Java code. Best of both worlds and all that.
Since I’m not responsible for your business, I say “Go for it”.