I don't have a 1400cs and so cannot really answer your question for sure, but I do have a 5300cs. What I can say is that once the screen resolution and colour depth are factored out, the 5300cs screen is as good as or even better than the passive matrix 12" Wallstreet's. Most likely that means that it compares favourably with that of the 1400cs (though again, at 640x480).
Mind you, that is not saying much, as passive matrix screens are generally disappointing for all but one use: working outdoors.