Fire druids are fun, no doubt about that. And they can be very good. But comparing these characters is hard, since the one gives physical damage with some cold damage from Hurricane, and the other fire damage with some physical damage from Volcano.
Winddruids generally have more chance of doing good in pub pvp games, because they can not be absorbed.
In PVM physical immunes arent common, and fire immunes are very common. But for that u could use a infinity merc, enough firefacets and (if still needed) a lower resist wand. It depends on what u want to do. If pvp i would suggest Winddruid since they are easier to play with and more effective.
Firedruids do have a high rating in the stylefactor though. But if u dont care about that, go for Wind