If fields of all items change at the same time, then using a single aggregated item will be more efficient. It might not be faster, unless the Server is under severe stress.

On the other hand, if you need that the updates for all items reach the client at the same time, then using a single aggregated items is the only choice, as updates for different items are managed independent of one another;
hence, updates produced in short sequence by the Data Adapter might be sent to the client in different packets.