The DX7s is a direct upgrade to the 6op FM lineup featuring a major redesign of the interface in an attempt to simplify the process of creating sounds. Even if settings were differently organized, the small LCD doesn't help at all, compared to the larger one available on the DX7 mk.2.
It was in fact released together with the DX7 mk.2, retaining the same shell, the new digital to analog converter and a large part of the functionalities. The lower price implies however missing stereo capabilities and layering, but overall it still doesn't feel like a simple repackage of the original 1983 synthesizer.
Touch control: inital touch, after touch
FM tone generator (6 operators, 32 algorithms)
Simultaneous note output
Polyphonic: 16 notes
Monophonic: 1 note
Voice memory: 1 bank x 64 voices
Performance memory: 1 bank x 32 performances
2 micro tunings
1 system set-up
Connection terminals and interfaces
Output Phones (phone jack)
Control jack: sustain, foot switch, foot control 1, foot control 2