TBH, The Korg series are really the ONLY arrangers that approach WS depth of editing. Little else comes close, and even there, the Korg editing and capabilities are far closer to older Triton-type editing that the latest Korg WS's like M3 and Kronos.

Right now, we have a gap that is killing the future of the arranger, IMO. On the one hand, we have the current market for arrangers, which seems to not really WANT depth of editing, more OOTB ease of use and minimal customization (the most successful arranger brand is also the least tweakable, on the whole), and, at the same time, the youth market is wholly fixated on WS's, with very deep editing possibilities, but little live ease of use or musical operation of arps and loops.

I see the only way for the arranger to survive, especially in the US market is to turn it into a MODERN music device. I'm afraid, you put a keyboard in front of a kid in his twenties with more foxtrot styles in it than hiphop, he's going to laugh his ass off! Look at the CONTENT that modern WS's have, their arps and loops. You MIGHT find a few Latin patterns, maybe a few swing things, but probably at least 90% of the content is techno, hiphop, rap, alternative, modern R&B, things like that.

Overall, there's nothing WRONG with the arranger as a musical device. But the manufacturers have relegated it to an old fogies' machine by their choice of CONTENT, and the stubborn refusal to include even a simple arpeggiator, let alone the more complex ones found in MoXF, etc..

Until that content disparity is addressed, it's going to remain a niche product in the States, and more a schlager machine in Europe. Of course, you have the problem that the people making arrangers now don't WANT to blur the line any more, because things are already working out quite nicely for them. You want a WS and an arranger, you have to buy TWO keyboards. Profit!

Only an independent has much of a chance of breaking this stalemate. I had high hopes for the MS, but it doesn't seem like Lionstracs have deep enough pockets to develop and content this up to what's actually needed, so it has returned to more of a WS paradigm, and content is very hit and miss. And, before anyone chimes in about how you are SUPPOSED to develop your own content for it, examine the absurdity of that... Yamaha, Korg, Roland, none of the major players in the WS market sell a keyboard where it is up to YOU to make the basic content. Everything successful comes OOTB with enough high quality content to keep those that are creatively challenged and technically limited still able to create high quality music. Yamaha would only sell a FRACTION of MoXF's if they came basically empty (or with poor content), they at least have figured THAT out, unlike Lionstracs.

Maybe Ketron can take a shot at it? They don't currently make a WS... Plenty of opportunity to take a stab at the market. TBH, they already HAVE an arpeggiator (though it could do though with a more elaborate one), so they are halfway there, they can do audio loop slicing and playback (but it needs a better user front end for them to put their own loops in), they have key triggered one shots (essential for hiphop and rap), they actually have most of the pieces.

But you STILL can't sell something full of bachata's and bolero's, foxtrots and waltzes to a kid! They would need to clean house COMPLETELY of all the legacy styles, and fill it to the brim with modern rhythms. This, I honestly think would sell like hotcakes. But one quickstep would queer the pitch completely.

Will we ever see it? It depends... I think the demand is there. Is there the will to make it? That is the big question, isn't it..?