I have the Zephyr Monsoon II with the LED lights on it. It has 6 speeds, though speed #6 is called "Burst" mode and will only run on that high speed for about 5 minutes before going back to speed 5. We mostly use it on speed-3, it is fairly quiet on that speed, but honestly this is my first hood. We used to have a OTA microwave with the hood built it, so that is all I have to compare it too. So far with it over our 36" BS rangetop with 6 burners we love it and it does all I need. I have only had to use speed-6 one time when I was using a griddle and forgot I had it on to high and it started to smoke. In the past we would set off the smoke alarm in our kitchen area with the OTA micro-wave one, we have yet to do that with this hood, as expected. Phil

What do you mean by "not utilizing the space"? Do you think the insert is too small? It heats 1,000 sq ft. Is that not enough? I have a Regency F1100 freestanding stove and I use it as my main heat source here in Vermont. Bigger is NOT better when it comes to wood heat.

I have a gas fireplace and the brick right above the fireplace still gets some black soot. But my white mantel (which is closer to the fire opening) does not. But I also have a regular wood burning fireplace in another room and I don't think you will have a problem. You could try it and see if you get any smoke build up and just stop using it as soon as you see black on the bricks. I doubt it could get to your mantel since its so high above the opening. But if you keep it regularly cleaned off, it shouldn't stain your brick. You probably don't retain much heat from vented gas. It goes up the chimney like the wood fire does. But after growing up with real fires, I love my gas fireplace since I don't have to do any work to get a fire. My only beef is that the logs get lots of black soot on them and I have to clean it off at least once a year. It stains the ceramic logs and that can't be removed completely.

If you aim for a serious amount of heat, you need to get a direct vent insert. These cost at least $2K. They are energy efficient in that most of the heat does not go up the chimney like the typical gas logs that look nice but do not give out real heat. And stay away from unvented systems which are a safey hazard and outlawed in many places. Do a search of direct vent on this forum to find out more.