I am on Gandara. For me it has been nice EU server. We are currently on wvw tier 3, this means we do not have wvw ques like higher ranked servers, but we still have plenty of people for dungeons, events, wvw, etc. When entering on LA (main city) or event areas you are often put on overflow (copy of map where you can continue to play when map where you tried to enter was full). Specially now when we got new content (patch).
Remember that if you aren't happy with server you choose at start:
- you can always swap server for free if you delete your characters (all bank items stay and are usable on new server).
- you can visit other servers (only WvW is not available when visiting /questing on server that is not your home).
- you can buy gems with in-game gold or IRL money to transfer all your characters(+items+bank) to new server.