I have the 55-300 but it doesn’t get too much use. The lens is good, no question about that, very light and a bargain at the price. For me the range of focal lengths I mainly use is overlapped by my Sigmas (previously the 150-500, now the 50-500). But I use the 55-300 when I need something lighter, for example when I’m skiing and don’t want to drag along the Bigma, or when I’m walking in a city and don’t expect to need a long lens (but I end up needing one). This summer it has also been my kayaking lens, to be used with the D90, as I don’t trust my kayaking skills enough to take the D800E and the Bigma.
If you can live with its limitations (adequate but not lightning-fast focusing, no manual override in AF, incompatible with polarizers due to revolving front element), I can easily recommend it.