An obvious consideration for active fin stabilizers is their position. While this is totally in the hands of the skipper and not a drawback to the fins themselves, there have been occasions when a fin was ripped off on a rock or other obstruction. The most recent case I've heard about was during a Puget Sound-SE Alaska Grand Banks-sponsored cruise a few years ago. One of the participating boats was a GB66, a boat that in my and a lot of other people's opinions should never have been made. GB made three of them and then I guess realized their mistake and didn't make anymore. The reasons are not for this particular thread.
But during this cruise the GB66 got too close to a rock or reef either entering or leaving an anchorage, tore off one of the large fin stabilizers and the resulting hole and ingress of water threatened to sink the boat. Only the fast action of a very experienced GB rep and shipwright (IIRC) saved the day.
The moral here is not "don't use active fin stabilizers" but "don't hit anything with them." Not as much an issue I would imagine in open water or places like the Gulf or eastern seaboard, but perhaps something to keep in mind in the narrow, rocky passes and entrances we can get around here and up into BC and Alaska where the water can go from real deep to rocks in a boat length or so.
Hitting something is almost always a helmsman issue, not a boat configuration issue, but depending on where one boats having a fin projecting down and out from each side of the hull can be one more thing that's important not to forget about.