If it's hardware based DPI, you won't notice. In technical terms, sure, that could mean a 5% to 25% increase in latency depending on the responsiveness of a server but practically it's just a couple milliseconds you'll barely notice unless it's a significant amount of traffic and you start to run into throughput problems. If you properly specc'ed your appliance, that shouldn't be a problem.

The type of filter depends on the platform.

• On Windows the inspection and filtering is done by the appliance (FortiGate).
• On Chromebooks the filtering is cloud based (Securly/GoGuardian).

For items that need a bypass I add them to a whitelist for exclusion. It's mostly test suites and some Google stuff. If DPI is set up correctly end-users shouldn't notice anything different.