Greetings all! Excellent board. My kind of people here. Purchased a regency gci60 a few weeks back. It is an insert, exactly like the enviro m55. I chose this model based on reviews, and that the surround works in my fireplace. I have it installed with 4 inch liner to the top of the chimney and no OAK. I do have a large opening in the fireplace which is the ash cleanout. It is flowing air like a champ from my basement/garage which is very dry. I did not use a manga helix yet, but flame looks good and heat is there. I have a remote thermostat set up which works well so far. It lives one room away from the insert, near the stairs. I have run a few bags of green supremes just to see what's what, and the thermo has been firing the stove up night with the thermo at 70. -72. Not much running during the day down here just north of NYC yet. Last night was the first test really. I have 2000 sf to heat, and with a low of 30 out, and with setting on medium heat, no problems getting the lower level above 70 everywhere. Just for laughs, I put the setting to high and thermo to 74 in the next room, and the house generally was warm to hot with outside temp around 38. 90 degrees in the room with the stove. Unreal. I have 2 tons of pellets on hand, including green supremes, cubic and omallays. I am hoping to get another ton or so of somesets or something similar. Green supremes are making heat, but appear dirty/dusty. Dialing in the stove I had a scoop of unburned pellets building up, but now it is mostly ash and few clinkers. I think it is running fairly efficiently.