I've been very pleased with my 2007 Komfort trailer. I've read a lot of information about Komfort having been bought by Thor and then quality went downhill but that most "rumors" seems to be spread from people who never owned them.
Has mine been trouble free and maintenance free? No. I had an issue with my slide to where the main ground for the slide switch/motor was extremely loose causing issues with the slide inconsistently working, although ultimately that was an easy fix, just took a long time for me to locate the problem. Yes, I need to reseal the roof seams for preventative maintenance, but what box style trailer doesn't have to have this done?
My trailer is of the heavier build with a single slide and GVWR of 9500 lbs. That is a 26' cabin, 30' overall length. Heavier yes but it is also very solid and seems very well built. So, I do not agree with the Komfort after Thor downhill comments. I intend to hold on to mine for another 5-10 years and will probably move on to a truck camper once the kids have moved out.