Making a living with an instrument doesn't make it "professional"; it makes YOU professional.

I think there is some crossover of meanings between PROFESSIONAL and COMMERCIAL. In that sense, "build quality" MUST factor into it. The equipment used by a PROFESSIONAL lawn service company is not the Sears or Wal-Mart special you'll find in your neighbors garage. You COULD make a living with it but you won't see many professionals using it because it's not "commercial grade". Will it (Sears/Wal-Mart) do as good a job cutting your lawn? Well, yeah, FOR AWHILE. But there must be a reason that "pro's" don't use them, just as there is a reason that most professional musicians don't (or won't) use arranger keyboards. Look at the Tonight show band, or Letterman's, or MTV, or 99% of every live music venue, and see if you can spot an arranger. Check all the music mags and see how many arrangers (if you can find one advertised) are endorced by professional artists. That should be a clue.

Ian is right, of course. And although you'll get the expected rebuttals from (what else) a group of hard-core arranger enthusiast who, of course, want to see their instrument of choice "be all that it can be", the proof is right in front of our eyes should we choose to embrace it.

Does the fact that they (arrangers) are clearly targeted at and marketed to, home users, in any way diminish them as legitimate musical instruments? Well, apparently so, at least in the eyes of professionals who have made it to the "next level".

So, does this mean that this "home user" instrument can't have "commercial" build quality? NO.

Does it mean that it can't employ the same (or greater) technology as it's "pro" brothers? NO.

Does it mean that it can't have the same level of complexity, flexibility, or even playability, as it's "pro" brethren? NO.

So then why can't it be considered "pro"? I don't know. Maybe it's like the difference between art and porn; it's hard to explain but you recognize it when you see it. JMO.

chas