I prefer onboard editing. Without a sophisticated player in the software, you have to tweak, port back to the arranger to try a full song with it, rinse and repeat ad infinitum. Not to mention, many arranger players tend to be on the elderly side and a bit computer phobic. And some of us use Macs (bet you no Mac software!).
The thing is, genesys, if arrangers boil their feature sets down to what the lowest common denominator wants (basically, nothing but good styles), most features on any arranger would disappear. Few edit their sequences. Few use multiple Intros. Few use the Songbooks, hardly anyone ever uses the samplers, many don't use the harmonizers, many stick to just the OTS (no need for live patch selection ), no need for a chord sequencer or track, no need for looping fills, the list goes on and on... Heck, I bet well over half of ALL arrangers dial up a Free Panel setting and never change it... Who needs registrations, anyway!
The point is, while many don't use style editing MUCH, a lot of people use it a LITTLE. But you never know which editing tool you are going to need. Without style event editing, so many simple things that can ruin a conversion or making your own fills are impossible to fix. And those of us that DO do a little style editing need these, even if we don't completely roll our own.
If I were you, to be honest, I would be VERY cautious about broadcasting, for WHATEVER point you want to make, that virtually no-one uses the style editing on their arrangers. Because if the manufacturers start to take that seriously (as you seem to do ), you can be sure they will drop them completely. And then, where will YOU be?
YOU need detail style editing, we ALL need detail style editing, no matter how seldom we use it, or what we use it for. That's ALL they need to know. Trying to cut the rug out from under those of us willing to make some noise over their non-inclusion on the Audya could come back to bite you in the ass. Just be grateful SOMEONE is willing to fight for what you use daily.
Or be prepared to be like me, howling in the wilderness for the return of my Chord Sequencer... Another feature few used, despite it's it's essential nature to those who DID.
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An arranger is just a tool. What matters is what you build with it..!