Yes, I think you need to have a gas stove to be able to use one of those flat grills. And I would definitely prefer it to my Lodge cast-iron grill pan
, but unfortunately I also have an electric stove. The primary difference between the two is the amount of space you have to work with. Otherwise, I don't think they differ that much in their functionality.
Do you have any specific concerns about using it? Considering how inexpensive these things are, I think they are worth having in the kitchen even if you don't plan to use them that often. It beats having to light up an outdoor grill in the dark (if you are cooking on a weekday after work) out in the cold. Although we can still do that here in California.