I just got mine a few weeks ago and its easy to set up. Just a few screws make sure its level.
The disadvantage that I have seen it that the plants don't get that continue light penetration that a fixed light gives you.
The other dis is if you have a hight issue. The motor and track will take away about 6", not including the chain to hook the light to the motor.
The Advantages is that you can spread out the plants or just have more plants that will get the same amount of light as the next one.
I would also rec. not buying the chain driven one.