I've been working with Python / Behave for around 3 years now, python's flexibility in what it can drive has been crucial.
Behave's flexibility on the interpretation of the Cucumber has also been very handy - there's a simple match mechanism, but if required it's possbile to go to full regular expressions and use those, and define choice fields too (where a specific parameter can be locked down to specific choices). Additionally, it's possible to automatically generate some smart, searchable HTML documentation on the library of cucumber phrases using simple tools.
Prior to using Behave, I hadn't worked in BDD or done much work in Python. I'm impressed with what the combination can do: in my case, it's driving selenium, C# assemblies, and several C API DLLs, as well as a training-set driven Python audio characterisation library, and it seems to do this pretty well (it's a highly complex system).
I haven't tried other languages (Java, etc) but I can definitely recommend Python / Behave.