BUKKIT-2038 still a problem. Until fixed, players are teleported one tick apart so you will need at least 10 seconds of countdown to give all players a chance to be teleported in.
Some features not fully tested. Please report a ticket if you find a bug.
There may be an inventory saving/reloading bug. If you find it, please post a ticket.
Maps do not appear to work in multi-world worlds, maybe a Bukkit bug?