Well, imho, while it may not be overpowered it is clearly out of line when compared with the other Domain Feats. That alone ie reason enough to consider modifying or not allowing it in a game. The alternative would be upgrading every other domain feat...
So, instead of having one cool domain power, your campaign will have none? I think most of the domain powers and feats are rather lackluster and not worth taking. So, having a pretty decent power that IS worth taking, but is also not overly powerful, makes the game more interesting imo. Just because the power is clearly better than other domains, it is not a good enough reason to ban it, but of course to each his/her own. With this logic, you should also be banning other feats that are clearly more powerful than others, like Weapon Focus/Mastery (+1 to hit/damage is obviously more way more powerful than say, a +4 to initiative). I'm playing an avenger, and so, instead of the old MUST-have feat of Melee Training (boring!), I now get this feat, which is super fun. Just my $.02.