I was just on a tour of Kerala and my first stop was the Bolgatty Palace. It was a truly beautiful experience. From the moment my wife and I arrived we were treated with kindness and grace. The natural beauty surrounding the old dutch mansion is astonishing. The palace is located just next to the river and the view from our executive suite was splendid.
The only complaint I had was the relative lack of good food in the buffet (which was included in our plan but at a hefty sum.) I would have rather spent the evening in Fort Cochin watching the Chinese fishing nets, having a beer, and dining on a freshly caught and cooked pomfret.
But over all the experience was a delight, Cochin in general is a delight. Stay at the Bolgatty for a peaceful and romantic evening but avoid the hotel buffet and go out for a bite (Although the taxi might be a bit expensive.)