AF uses the better materials, but we had a few quality control issues on ours. Some things were just put together sloppy and I had to fix them. Also a bit heavier than other similar brands.
The extra insulation and double glazed windows are great. I made to mistake the first time we took ours out and used flannel pajamas like I needed in our old Komfort. That was a mistake. I roasted. Even when below freezing outside the heater only cycled a few times at night. It stays warm on winter nights and cool in the summer.