[megakid]

We use this heavily in production and to good effect. It has its downsides (doesn't every product) but we have found it works well once you've grasped them. If you have a primarily .NET focused team, have plenty of event-driven applications and want to do CQRS / Event Sourcing for some of your applications I would recommend it as a starter step towards that. It gives you a lot 'out of the box' which is great when starting out but over-reliance on some of its features can make it hard to replace. Make sure you have a good handle on retention and an archival strategy. Storage maybe financially cheap but it's certainly not maintenance friendly once your database grows beyond certain sizes (we're currently running our own fork to solve some of these issues whilst the PR process is going on).

[rjbwork]

We just wrote our own on top of Sql Server. Runs fine for thousands of accounts with many events per day. We currently host it on the smallest azure sql scale level. We have virtually unlimited scaling with azure, and should have no problem sharding it in future because we include extra metadata (event type, accountid, etc.) so we could choose to shard on any of those dimensions.