Confusingly, there's also "Euro Bass Day", which takes place in Italy.
www.eurobassday.com
The Italian event has had players like Matt Garrison, Anthony Jackson, Adam Nitti, Mike Pope, Felix Pastorius etc - i.e. American players that don't make it to Europe that often.
Haven't been to either but either event but the Italian event has always been more appealing. More "name" players + bigger manufacturers attending.