I have an Edenpure. I think the model number is 1000XL. It's pricey, but definitely outperforms typical spaceheaters, while drawing about the same current. I estimated that mine costs about 16 cents an hour to run.
I use it primarily to heat my walkout basement when I'm planning to be down there. The area I'm heating is roughly 1,000 square feet. It'll bring the temperature from 64 to about 69 or 70 in 60 - 90 minutes, so we can watch television, gather around the bar, or play cards in comfort.
It's quiet, too.
In a smaller area, such as a bedroom, it heats it in no time.
Most houses are too large to rely on it to dramatically cut a heating bill, but it is a nice heater.