The Microsoft .NET Framework uses this method as the default. This option results in larger pages sent to the client browser since the view state is embedded in the page in a hidden field.
Process recycling has no effect: The view state is not affected by recycling of processes on the server including the worker process. Memory on the server is not an issue since the view state is not being saved on the server.
Slower on the server: The view state must be encrypted before being sent to the client browser and un-encrypted when it is returned. This slows down the application running on the server.
Additional bandwidth required: Because the page size is larger, this requires additional bandwidth.
Anti-virus programs have more data to scan: If the client system is running an anti-virus program (and most systems do), the anti-virus program has to scan more data during its scan to ensure that there are no viruses on the pages retrieved by the browser.
The page option slows does the server since the view state has to be serialized and encrypted on the server, and unencrypted and de-serialized at the return trip. The page option also takes additional bandwidth and slows down the client system since more data has to be parsed by the client browser.
One advantage of the page option is that the view state is not affected by recycling of processes on the server including the worker process. Memory on the server is not an issue since the view state is not being saved on the server.
View State Storage Options for Improving Performance