I quote a post on SynthZone:
"Here's some information on comparing the new PSRSX900 and the PSRS975:
FSB Organ, initial touch keyboard action
Color touch screen user interface
Joystick controller (vs. modulation and pitch wheels)
1337 Voices, 56 Drum/SFX kits, 480 XG (vs. 1090 Voices, 55 Drum/SFX kits, 480 XG)
R1, R2, R3, L keyboard parts (vs. R1, R2, L only)
8 insert effect slots
Master Compressor & Master EQ with 30 user settings each (vs. 5 user compressor and 2 user EQ)
Chord Looper function
Style Section Reset function
Bluetooth audio
1GB expansion Voice memory (vs. 768MB)
3MB per MIDI song capacity (vs. 300kb)
4GB internal memory (vs. 13MB)
WAV and MP3 audio recording (vs. WAV only)
329 Multi Pad banks (vs. 308)d
Main L&R line outputs, plus Sub L&R line outputs (vs. Main L&R only)
(15W + 10W) x 2 amplifiers (vs. 15W x 2 only)
USB to device x 2 (vs. x 1)
Playlist (vs. Music Finder)
Comparison of PSR-SX700 and PSRS775
PSR-SX700
1337 Voices, 56 Drum/SFX kits, 480 XG (vs. 986 Voices, 41 Drum/SFX kits, 480 XG)
8 insert effect slots (vs. 5)
Chord Looper function
Bluetooth audio
1GB expansion Voice memory (vs. 400MB)
4GB internal memory (vs. 1GB)
329 Multi Pad banks (vs. 226)
Main L&R line outputs, plus Sub L&R line outputs (vs. Main L&R only)
Expansive Sound Field speakers
(15W + 10W) x 2 amplifiers (vs. 15W x 2 only)
USB to device x 2 (vs. x 1)
Step Ups To Higher Model:
Genos
9" TFT Color Wide Touch Display (vs. 7" non-touch)
OLED Live Control View sub display
6 Assignable Knobs (vs. 2)
9 Assignable Sliders
6 Assignable Buttons
AWM Stereo Sampling + AEM Technology (vs. AWM Stereo Sampling Only)
Super Articulation 2 Voices
Revo! Drums
Ensemble Voices
28 Insertion Effects
_________________________
George Kaye
Kaye's Music Scene
Reseda, California
818-881-5566
www.kayesmusicscene.com"
End Quote
Oh Boy, that will be a fine Xmas gift, Thnx Santa Claus ;-))