I have played on several experimental servers, some of which had reset multiple times. I have kept the same character, and playing with a friend who lost his every time the server reset we finally found out why.

If you log out of the game for a bit, it will save your character details. I have tested this now through 4 resets. Each time I come back as the same character with the same gear at the same location that I logged out. Each time my friend who had not logged out, lost his character and had to start new.