I think the sound will match that of Genos.. its the exact same engine..

However it misses all the features that make Genos pro..
- 76 keys fsr keybed with aftertouch
- sa2 voices
- some organs like the Wersi one that i use a lot
- ensemble voices
- some dsp power
And more..

I don’t think people that aren’t used to Genos will miss them much, but for me they are worth the extra money..
I guess comming from the psr-s975 the SX-900 will feel like a near perfect instrument..