Just installed a Quadrafire 4100I about two weeks ago. After reading 100's of positive feedbacks on Quad's, two years of research, and finding someone who had one that I could actually talk to about one (turns out I worked with him for 12 years and didn't know he had one) I finally decided it was the right insert for us. The first time I lit it,it was true bliss to finally get some heat our of the fireplace I installed when we bought our house. I have read a lot of suggestions on hearth.com from cleaning glass to figuring out the correct air setting to really get the heat going. Thought I would send out a thank you to every one here who unselfishly offered their years of experience. THANK YOU ALL.