I was always of the view that these arranger things made no sense and didn't really understand how this type of keyboard could really benefit me. I saw them as mediocre to poor at best and targeted toward beginners only.
I mainly use macbook pro running logic in conjunction with a Kurzweil PC3, Waldor blofeld, and Elektron monomachine. I have several other keyboards that are older or very specialized and don't use them as much.
This is my first arranger and a fantastic one, it truly complements what I have extremely well. The sounds are very good and the styles cover a broad range including oriental. I am more accustomed to workstations & synths and although those offer greater depth in waveform manipulation I.e. creating a specific unique sound, this board has an immediacy about it that makes it easy to just want to play. This board has a great interface that is simple to learn and navigate. I have a total of 12 keyboards and this is by far the easiest and most accessible for getting ideas down quickly. I especially like the fact that styles, midis etc. can be revoiced easily and pan/gain/effects changes are at your fingertips (a computer is only in the way in this case when I am just brainstorming). The really unusual feature and a major reason why I bought it was the scale tuning capability. Now I can create something very different quickly and learn what works and what doesn't in that process - believe me this throws an entire new spin on everything and makes me rethink what I already have learned musically. I am into ambient, electronica, and experimental type music. so this complements my other hardware.
Is it the best arranger - probably not for most people, but for those looking for something that gives them immediacy and an alternative perspective on creative music composition, this it it!