I have the same question ... can anyone else weigh in on this thread

What is the size of the room you are going to be putting this in? Also what model Napoleon and heat-n-glo are you looking at? If you let me know what the models are, I could be more help.

Silly me, I just saw the models were in the title. Yeah they are fairly similar. The big draw back of the heat-n-glow is there is only one approved vent pipe for it, Hearth & Home
Technologies DVP venting systems. Napoleon allows you to choose from 5 different manufactures vent pipe such as Wolf Steel, Simpson Dura-Vent, Selkirk Direct Temp, American Metal Amerivent or Metal-Fab
venting components. So you might be able to shop around and save some money on the vent pipe and the other manufactures might have different parts to help out on a unique installation such as wolfs steels flexible vent pipe. I dint see anything about heat-n-glow warranty, I know Napoleons are a lifetime warranty. Heat-n-glow does have options for fire glass though, Napoleon doesn't. Heat-n-glow to me, would have a tad more modern flame look, where as the Napoleon would be more traditional. Hope this helps.

We just bought the napoleon LDH50 and had it installed -- Haven't turned it on yet since the gas lines aren't connected but it looks great! We didn't really look at the heat n glo mezzo -- no dealers had it in our area -- but we did look at the heatilator crave (which I believe is also owned by heatn glo). Although my favorite fireplaces were the marquiz 60" and element 4 Luicus 140, those were out of our budget, and I am very happy with our choice.

One big plus to the napoleon besides price is that the LDH50 is being phased out. That means they were all produced before Jan 1, 2015 and aren't required to have the built-in safety screens. I'm sure you can get two if you need them -- but I prefer the look of the fireplace without the screens when not in use. The heatilator was more expensive and had a bulky screen that interfered with the modern aesthetic.

Good luck!!! Remember to pay attention to the vent size and venting requirements. We had to build a chase in one of the closets to house the vent, which our architect hadn't initially thought of.

I, too, bought the LDH 50 after weighing a bunch of options. For us the heat output was secondary to the streamlined, modern look, though when we were at the showroom it seemed like plenty of heat was thrown off. It hasn't been turned on yet either! But it looks good...