Hi Quitpic1:
I currently own a used PSRS-S910 and a used PSR-2000 (Yamaha) and have owned a Micro-Korg. The 910 will run rings around the 2000 and I gave up on the Micro because of the learning curve required to transition. (It was a nice little board and I loved the size... reminded me of some of the very early PSR Yamaha models.)
I'd love to own a PSRS-S950 but your question about a smaller arranger is most interesting to me. I am a songwriter and never perform or play to an audience... so I could do without speakers as long as a headset port is included. USB is a must and that would include firewire USB as well. The length of the keyboard is not an essential element for me. I only play chords with the left hand so the rest of the keys are normally unused by me except on rare occasions.
I absolutely love the color display and would even like it better in a larger size. I've grown so used to Yamaha's general layout I would like to see that continued in my dream-yammie-micro but could stand some of the features moved to the left hand side to reduce the length. I especially like the rubberized buttons... prevents noise in the microphone when recording.
I would also love to see a USB stick port on the front of the machine to allow easier importing and exporting of styles, multi-pads, etc.
One of my biggest complaints about Yamaha is the lack of bluegrass instruments such as a flattop/dobro guitar and more modern sounding styles for this genre. Many modern country songs are featuring dobros or flattop resonator guitars in strategic points of a song such as breaks, intros or endings.
I also hope that in the future, Yamaha (and others) will use the color display screen with easily identifiable layers for making song arrangements easier. Each time I write a new song or composition, I have to reset the pan buttons as though I were an orchestra leader with the instruments "aimed" directly at the center (the conductor) or have a feature that would allow this as part of a global setup.
I could also live without Yamaha's recording arrangement because I use a dedicated digital recorder in lieu of the onboard unit. (space savings)
Forgive me as I dream... I know I represent a very small customer base... but Yamaha or others could exploit this new configuration to songwriters if they would put forth a real effort to "educate" salesmen at the big box stores to understand how arrangers are different plus how styles and multi-pads can enhance a song demo. At last count, there are more than 75,000 songwriters in the USA alone and a target price of less than $500 dollars would probably be a "home run" for them, monetarily.
I'm sure there are many other cost cutting changes many of you can envision... but please remember, my ideas are aimed at song writers or composers.
All the best,
Dave Rice