I've had my 44Elite since 2003. I haven't had any real smoke issues unless I fire it up without warming the chimney. Ie. operator error. Seeing as it burns pretty much 24/7 when the ambient temps are less than 45* it's not an issue. The unit heats my 2 story 3100 sqft home pretty evenly. When it gets down below 20* heating the outside air takes some efficiency away, but it still works very well. You are correct about removal being a major task. I had a crap-o (technical term) zero clearance removed and the FPX installed one year after building my new home. To see guys working with jackhammers in my brand new family room was a bit disheartening, but very much worth it. I do recommend getting a temp sensor. It takes the guess work out of combustor operation. Here are some before and after pics.