I don't know about that particular model but i really like Kawai pianos in general. I very nearly bought one last year. I think they are quite robust, well made instruments.
Although if yours is secondhand i'm afraid it's difficult to say. 1990 isn't too old though, as modern pianos are built to cope with modern things like central heating etc so it should stay in tune fairly well (depending on what condition it is in, how much it was used before etc).