I only brought Zuki into this because he is as fervent a Yamaha zealot as Fran is for Roland, but with even less posted material to demonstrate it.
Somehow, zuki has no time to record himself, but plenty of time to post irrelevant 'Yamaha is the best!' on any topic he feels like, relevant or not.
C'mon. guys... Let's get real. NONE of these arrangers are 'the best'. They ALL have features that could be improved. They ALL have areas of soundset that could be improved. They ALL have OS problems that could be improved. They ALL have layout problems that could be improved.
There is only one person they are 'the best' for... YOU

I've said this many times... They are NOT your grandkids, or your girlfriends, or your religion. They are TOOLS. No more or less than a spade to a gardner. It is the gardner, NOT the spade, that makes the garden. Now, MAYBE, in gardening circles, there are some who will go 'my spade is the best!' but somehow I doubt it. There are FAR more important aspects to gardening than what spade you use.
And, fortunately, in music, what arranger you play is probably one of the least important aspects of how good you are, either at just playing music, or at entertaining a crowd. The audience doesn't care whether you play a Casio or a T2, as long as you entertain them. And we have ALL heard a great arranger in the hands of a terrible player.... It sure didn't sound like a great arranger, did it?!!
Just the simple fact that everyone goes gaga every time one of the majors releases a new arranger demonstrates that everyone DOES want an improvement to their arranger, that there IS room for improvement, that PERHAPS the arranger they have now is not PERFECT...
Now if only we could be adult enough to admit this BEFORE they come out with the new models...
WHEN someone comes out with an arranger that is all around better than the one I have, in all the areas I consider important, I will get it. And I won't give a d*mn whether it is by Roland or Yamaha, or even Casio. I won't be changing religions...
I will just be buying a new tool.