Recently I bought Sena SF4. Very nice device. Though the current Dutch voice version inside is very "bad". I mean, not in a technical way, but just from the user experience. It feels like machine-generated, and it's not very descriptive either; for example, 'battery empty' is just 'empty' in Dutch.
I would be glad to supply spoken voice instructions for Dutch Sena Firmware, but with better sentences and a real voice. My wife is Dutch, and we can record voice messages. We are willing to do it for free. I think this is going to be really helpful for Dutch-speaking SENA headset users.