It depends, awhile back people complained of fires. I think this was only with the Halide lights and it seems since they switched ballasts, not a issue now?
I started out with a PC fixture years ago and it was fine. I'm actually fixin' to order one of the $70 48" led lights for my FW tank to see how it does. The thing with the cheap lights, most will put them down but probably 90 percent of the people who do put them down, never even owned one.
Steve