I think I would prefer to have one no-compromise arranger, and a no-compromise workstation, than one keyboard that was the best at neither....
If and when a perfect hybrid keyboard ever gets made, sure, I'll give it a go, but in the meantime, to get hybrid capabilities, it seems SOME sacrifices have to be made. I certainly don't want to have to do months of work on an XS to give it the full arranger feature you think it MIGHT be able to do (and I completely disagree that it IS capable of most 'normal' arranger capabilities, despite having chord recognition), if I could go out and get a T2 or G70 off the shelf and it already have those capabilities.
The thing is, most arrangers are more than just sounds and styles. It is a philosophy of live 'ease', of being able to call up a new style while one is already playing, of muting parts within those styles quickly and easily, of calling sounds up for keyboard playing quickly and seamlessly, of not worrying about large jumps in volume between different patches (the bane of workstations, OOTB!), of having easily accessible songbook database functions for large repertoires, of on screen lyric displays... And so on, ad nauseam.
There's a LOT more to an arranger than styles...
Workstations (whether they have loops and chord recognition or not) seem to have a philosophy of 'if you have enough time to prepare for a gig or song, there is nothing better'
Arrangers have more of a philosophy of 'if you have NO time to prepare for a song or gig, there is no better keyboard'...
I agree that with enough time and patience and flexibility, you COULD make either do the other's job. Just not well, so why bother..?
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An arranger is just a tool. What matters is what you build with it..!