The summary screen is one of the most useful sections. It provides easy access to some vital information to help you debug both SPF and DMARC issues as well as access to the monthly PDF reports.
The SPF record section allows you to visualize all of the IP's that are sending emails on your domains behalf. This include both IP that are authorized via SPF and IP's that are not included in your SPF record.
IP's not in the SPF record are typically the first place that we look when trying to determine if a domain is ready to switch to DMARC quarantine or reject.