We have a fireplace in our 5er. We love it. I only use it when we are on the generator or when we are plugged in. Since it is electric, it draws allot of Amps. It is quiet and heats the trailer nicely. It looks nice and is functional. I highly recommend you don't mount is under your TV. The heat from the fireplace will eventually damage your TV.
We were looking at RV's and the wife found the one we bought because it had a fireplace. I'll never forget her statement " This is it we don't have to look anymore this is it." Since we all know what the wife wants she gets, we got. BTW there were a lot of other things we liked too. We're fulltimers now and staying in a state park with electric hookups and we use it to heat the place up. Propane is going the way of gas prices-up!!!! I talked to someone at a U-Haul place in Colorado Springs,Co. and they said propane was $2.10 a gallon, so this is a nice option to have. While we were in Quartzsite we bought a catylitic heater to save on propane and that heats our rig up nicely.