I enjoy the FSO's because the focus is air combat with defined mission strategies taking place. (no GV's...no base capturing etc)..... Its also one of the only times where your entire squad might show up to fly together....
The melee arena doesn't really have a focus. I think there is just too much going on, GV's....ships....base taking... air combat. Its fun once in a while, but now,for me, its not focused enough to make me want to spend a lot of gaming time in there.