Hi Stephen,

You would certainly enjoy having the portable Roland RD-88 weighted action digital piano as a worthy addition to your collection of top-of –the-line Arrangers.

Since you have already owned the Roland FP-90, you are familiar with the silky smooth action of the PHA-50 keybed utilizing wooden keys. The plastic keys on the RD-88 sporting PHA-4 action does not quite match up, although they feel adequate enough.

The Yamaha DGX670 is the best 88-key arranger at the $850 price point. The key action is slightly better than the Yamaha P45, which has pretty much established itself as a solid beginner’s piano.

The textured keys with the PHA-4 action on the RD-88 feels better than the Yamaha DGX670.

The RD-88 has key escapement. This brings it closer to the touch of an acoustic grand.

Since you already own the GENOS and the PSR-SX900 along with the Yamaha CVP-307 Clavinova and Korg Pa4X it may be superfluous to add the DGX670.

You could use the RD-88 as a portable controller for the GENOS or the PRS-SX900 or the Pa4X.

The Yamaha DGX670 will be too bulky and heavy weighing in at 47 lbs.