I agree with you, and I hope Delight will be very useful!

We're showing new metrics (CPU & Memory) that you couldn't get in the Spark UI (you had to use something like Ganglia, and then jump back and forth between Ganglia and the Spark UI by comparing timestamps).

We alos hope to display this new information in a way that will make it more easy for most users to get insights. Make problems more obvious, more quickly.

Let us know your feedback!