Svix makes it trivial to add a custom webhook portal for each of our users. We even use it internally as a replacement for SNS. Customer support is very quick to respond on Slack.
In terms of performance and relability, we use Svix in production and it handles hundreds of thousands of requests flawlessly.
Svix is easy to integrate and provides a robust, highly available service. We were especially impressed with the Consumer Portal and the out-of-the-box React hooks for building deep integrations in our application. Our customers like the transformation; it makes it easy to integrate our webhooks with external applications.