Thanks for the input. As I mentioned in another thread...I bought these four month old Borresen X2's from an owner who had ordered big Wilson speakers and wanted something in the interim and was curious about the Borresen brand. He always intended to sell the X2's and the Wilsons came in earlier than promised so the X2's only had about 20-30 hours. I've put 20-25 hours on them. The maker suggests 50-100 hours for break-in though I've heard higher numbers from some owners. I am going to take several more weeks burning them in before making a final judgment whether to sell them or the Focal Sopra 2's. For whatever reason, my Boulder 866 integrated with DAC and Auralic Aries G2.2 plus Audience Front Row loom lead to zero fatigue or tweeter irritation...none. The detail on the X2's is very appealing, better than the Focals, but I am getting a little fatigue from the X2 tweeter when the volume is up on some music.