My suggestions are:-

1). Make use of the Hi/Lo eq settings on the accompainment part, increasing the hi/lo
together gives a much richer sound.

2). Leave the overall eq set as preset one,
I have found extreme setting can cause the keyboard to sound unaturaly harsh.

3). Experiment with the part volumes in the accompainment section, they seem to be factory set in a fairly neutral state, sometimes fairly intricate embelishments can be lost because the part volume is too low.

4). On certain styles I have found selecting "ambience" in the dsp section gives a live and expanded sound, I use this with bigband styles mostly.

5). Most voices can be enhanced by increasing the reverb, obviously this is dependant on the room acoustics, the "classical or sweet flute" sound beautiful with a little more reverb.

6). Grand Piano - the original setting is slightly short on sustain and overbright for my liking, try altering the release setting, and turn the eq high setting to zero on the appropriate part.

7). Don't overlook the XG voices, I found I prefer the shakuhachi on XG voice section as opposed to the panel voice, their are lots of other XG voices that are also quite suprising.

8). I recently went to a WERSI concert, I was very impressed with an organ string type sound they were using, for a similar sound on the 9000 select rockinorg(from drawbar presets), sweet heaven and insomnia, try this and experiment with the drawbar reverb octave settings etc, the sound I managed to get is "big".(the superior polyphony of the PSR9000 means you can produce this type of sound with no dropouts).

9). Make use of the pads to embelish the accompainment, setting a pad to repeat can really fill things out, the DJ set pads are extremely good for modern dance music or Jean Michel Jarre etc. The Limbo dance pads really show off the "live" drums, don't forget the pads can be mixed, try playing the limbo dance pad 2, select the XG pad shakuhachi and use the pitch bend wheel for realism.

10). Obtain more styles and store them on a ZIP drive for instant access via the "disk direct function". I like a lot of the "1000 PSR9000" styles contained in the "PSR STYLES VAULT" also the yamaha italy styles are very good, some of them really eploit the DSP section. For newage type styles try www.svpworld.com, I have purchased all four of the available disks, they are quite a change from the regimented internal styles,
they have a real human quality about them, they are ideal for composing as they give you a good framework to work around.

11). The main thing with the 9000 is not to get in a rut with the "Music Database" I find it is a good starting point for seeing what can mixed with what, but you will get the best results by exploring different DSP settings, voice editing and volume balances.
I think I'm right in saying that the 9000 has the most comprehensive DSP's of any of the arrangers, therefore I don't think it's surprising that the factory presets probably only exploit a fraction of what can be obtained, maybe if release date was delayed by a year the factory presets would have been better.

In my opinion the only better arranger at the moment is the 9000pro, I do have itchy feet about upgrading, but I also have this niggerling defiance that I don't want to line Yamaha's pockets with more of my hard earned cash (certainly not after only a year with the 9000).

I'm not a pro or even semi pro, I just love playing music for my own enjoyment and the enjoyment???? of family and friends, the 9000
just gives me a lot of inspiration because I know it has a lot of potential and what is most important a good set of quality voices, a keyboard can have all the flashy styles you like, but without a wide selection a quality voices it is really just an expensive toy.
I hope I have gone someway to explaining why I still think the 9000 has the "wow" factor
(for me anyway), because "wow" is what I usually say when I discover a new combination of sounds/effects.
Sorry about any "tie pin" errors but this screed with rushed out on the fly with no preparation whatsoever.

Paul.