Bill, I guess my only take on that would be that, if you tried and rejected EVERY arranger out there (but returned reluctantly to where you started in the first place), then perhaps an arranger keyboard isn't what you are looking for...
Maybe it's a REAL backup band, that plays everything EXACTLY the way you want it (because you arranged and rehearsed it that way!). Or is that too old school?
Sometimes I feel we all expect just a BIT too much from these keyboards. They are, after all, mere machines, trying to accomplish something that in the past took talented players and talented arrangers (the human kind!). They can get you close-ish, but they'll NEVER get you all the way there. If that's what you are searching for, I think you may be doomed to perpetual frustration.