@Sayantan
Hello,
A choice like this is so personal. From us responding to your question, you'll get our impressions/tastes/opinions which may match yours and may just as well not.
As has been said, these are four reasonably good digital pianos. As you seem to have now narrowed down to the Roland and the Kawai, I personally would pick the Roland.
For about the same price (apparently where you are), it is better built (the "furniture" as well as the action) and nicer looking than the Kawai.
The Roland's action may feel a bit heavier to play than the Kawai's. On the other hand it feels more precise than the Kawai's, which feels less controllable and somewhat fluffy and bouncy.
Then there is sound: the Roland may sound a tad more synthetic, because it has a generated/modeled sound. The Kawai has sampled sound, sampled from a selection of actual Kawai pianos. The CA401's sound engine is simpler though than e.g. those of the CA501, 701 and onwards. To my ears, it's a bit of a hit and miss.
These are "just" my observations (from too many store visits and tryouts 😉). Trying before buying is highly recommended. You'd be surprised how different your actual experiences will be versus the ideas that have formed in your head from mining the internet.
Cheers and happy decision making,
HZ
PS The MP11SE as suggested by @Las , is indeed a serious option with markedly better action and sound than the CA401.
PPS Don't expect too much from the speakers. Contrary to what marketing wants to make you believe, they're generally disappointing across most brands and models, up to and including the expensive ones.
