Span Metrics are now generally available to all customers view the new Trace Explorer.

Head to Explore->Traces to get started

You can search for any span or trace samples

You can visualize an aggregation of any span based attribute such as p90(span.duration) or p50(file.size) and then even aggregate your metrics using Group By's

You can compare multiple queries, saved your queries or create dashboard widgets and alerts for them too.

Please see our docs to learn more.