Hi Fan,
Basically, the DGX-203 is very much like the PSR 292 except the 76 keys. There might be also differences in the number of sweet-cool-live voices but I dunno.

For a good touch sensitivity I'd recommend the DGX-305 with semi-lighted keys (I play this model) but it costs a few $ more.
The semi-weighted keys make a significant difference when compared to the ordinary PSR keys.

Hope this helps.
George