I don't think this is true. I also can't find any such testing done in any euro magazine. I am not asking this question to be a PITA. There is a local dealer telling me that I need to audition the Burmester gear and I raised this concern with him as well and I didn't get any re-assuring response from him. I don't think specs are everything, but they can be very useful in narrowing things down in relation to a particular pair of loudspeakers.
If you go to the German eBay and do a search around Burmester you will usually find many past magazines with reviews of Burmester equipment. But some people say that German is not easier than French to understand!