Just my 2 cents
The best arranger is completely relevant to personal taste, exactly like John said. I really, but really love my Audya. However, there are certain Yamaha styles that I miss sorely & that I cannot reproduce accurately on the Audya. I also miss the way the new choir voices are used on the Tyros 4. And most of all, I miss the ability to play intro's & endings one after another as many times as I please.
So yes, each arranger has it's strong & weak points. No ways will I ever let go of my Audya for the sake of something else, I'm just THAT satisfied. But in the same token there are some things I really miss from Yamaha.
Keep well all,