I think this has much more to do with how some people are perceived than whether some keyboard is 'pro' or not. For instance, some of us choose not to use arrangers in live performance. I'm one of those. I don't think a jazz club is the right venue for an arranger keyboard and at the moment, that's the only venue I play. That doesn't mean that I look down on arrangers or arranger players. It's just a question of the right tool for the venue. I also wouldn't take an organ trio into a C & W venue. I've invested over 6 grand in arranger keyboards over the last couple of years, and play one of them almost daily. I use voices from both in recording although I have at least several TOTL workstations (I like some of the arranger voices better). I also use one (PA1x) as the handiest of handy drum machines (traded my DR880 to Dan01 2 yrs. ago) for putting together a rough track. It's easier than the average drum machine. Working with singer/songwriters, I can flesh out a new/original tune in less than an hour. The arranger is a great tool, no doubt about it.
When I see some or most rational, reasonable, diplomatic, members, who themselves are seasoned pros, starting to get defensive and viewing alternative points-of-view about arranger usage, as being anti-arranger, then I know it's about time to stop having this discussion. Like I said before, who cares how someone else classifies your instrument of choice. JMO.
chas
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"Faith means not wanting to know what is true." [Nietzsche]