I believe Arranger Keyboards will stay at a basic level; in other words, they will still use styles (auto-accompaniment) which defines what they are.

If you can get into style editing, the instrument won't grow old so quickly. I know several players still using Tyros2's and PSR-3000's and have no intention of upgrading, mainly because they have learned to edit and re-assemble styles.

The Audya is another example of an arranger than could be considered a long-term investment.

I must say, I'm very happy with the level of my Tyros4, and it would take quite a lot to tempt me into buying anything else...in spite of having the T4 for a few years now and playing it extensively everyday, I'm still on the honeymoon.

Ian