Really going to depend on your climate. This model heats approx 15 sq feet according to the website. So if this is being put in a large room, in a cold climate probably won't perform much better than what you have now.

What ever heating apparatus you use, it needs to be properly sized for the structure to heat it properly. Think output capacity.

Nectre N60 Specs

Log size comes in at 420MM or about 16.5 inches. Normal standard fire place is 24" so using natural wood in this you may have to cut it to get it to fit.

Also what ever you choose make sure it's vented properly to the outdoors. I know this is common sense type stuff, but I never know who is going to read this comment into the future. So take it for what it is --- a warning.