I've had this piano over 8 months now (for an absolute BARGAIN brand new!) and I love it!! It's the perfect companion to my WK3000. Just a pity that you can't load extra user tones like you can with the WK3000, but then you can't have everything, and I use piano 99% of the time anyway.
The new PX 700R looks great too, especially as it retails for the same price and features 3 fixed pedals, but I don't believe it has the USB, Smart Card capability, nor line (mic) input (a feature I particularly like as I'm currently learning "Play Piano with Keane" and I can feed the backing track in via this) of the 400. All in all, I think I got the best piano for my needs and within my budget! Well done Casio yet again!!