Hello Dieselpark, I dont exactly have the same comparison: I used to own the XA160 and listened extensively to the X250. These pass amps are all very good, very smooth sounding and engaging. I would say the XA series gives you a bit blacker background and an "organic" sound. For me, I preferred the XA series. Keep in mind that these get very hot! I dont you think you could go wrong wit either but if you budget, system, and ears support it, go for the XA.
BTW, you english is way better than my German!
BTW, you english is way better than my German!