All.. for info:
I couldn't resist it so I bought one of the Elfin-EW10A. That's the one with internal antenna
It's now bidirectional connected to a AIS class A transponder, baud rate 38400, and set up to get a DHCP IP from my local router. Easy set up via a web interface.
Just now used on three PC at home. Works fine also with the internal antenna
through one floor ~20 meters away from the router.