Can the creators describe this product's advantage over FullStory and LogRocket? Also, it seems challenging to get this to work in production, since users wouldn't consent to this level of monitoring.

In its current state, Replay's not meant to replace either of those products as it's not meant for 24/7 user session monitoring. Instead, it's something that we see teams reaching for in their debugging workflow.

The usual bug workflow is for one person to file an issue with steps to reproduce, which the engineer will use to reproduce the bug and try to debug the problem. Replay replaces that workflow by allowing a person to record a replay, and send that link (which is immediately debuggable) to the engineer.