cside only adds 8-20 milliseconds (the blink of an eye typically lasts between 100 and 400 milliseconds) of latency to the specific, highly dynamic JavaScript files we proxy. Static scripts are cached at our edge and therefore load faster than the original source, improving the speed of your website. This is completely different from a WAF that adds latency to every single request to your website. Users won't notice any difference.
CSP is a great base-layer for client-side security, but it cannot see script contents. Depending on your needs and risk profile, it may or may not be sufficient.
PCI DSS requires monitoring scripts for changes. CSP can only control sources, not inspect payloads, so it cannot meet PCI DSS requirements.
We fundamentally believe every individual and operation should be able to secure themselves, regardless of resources.
Because client-side security monitors an entirely different dimension of the application stack, there is no interference.