Yes - having seen them used in Sweden, where winters are dark, I bought one there (Ikea). They seem to prevent seedlings getting leggy as they stretch towards window. Last January my OH started tomato seedlings very early, in the house with one of these growlights and we had tomatoes in our polytunnel much earlier than previously. We've also used in unheated (apart from frost protection heater) greenhouse.
As I can't seem to readily source the lights here (Ireland) I looked online. I was a bit put off by all the "growhouse" suppliers but ordered some which came from China, I think. They were OK, but not as good quality as Ikea ones.