Hi, Cyclotron developer here. I think it's fair to say Cyclotron is a bit more open-ended in terms of what you can build, whereas Grafana dashboards are a bit more structured and tend to look more similar. While Cyclotron provides common widgets and dashboard functionality, it also makes it easy to add custom HTML, JavaScript, CSS, etc. This broadens the potential use cases quite a bit. The downside of being more open-ended is that it doesn't provide the same level of rich interactivity out of the box, which Grafana does.

Additionally, when Cyclotron started, it supported pulling data from a handful of different data sources, whereas Grafana was focused on Graphite. Grafana has definitely come a long way in the last year in this regard though.