Web服务/ wcf服务，返回数据集是否更好？

So from what I've seen about services, custom objects seem to be the way to go when the service is written to return data. If I am writing a service that will be used to 1) populate a database, or 2) provide information for a web site, is there ever a use for returning a dataset/datatable as opposed to a list of custom objects with all of that information?So from what I've seen about services, custom o