As I said before, not only for Spectrum, but for any monitoring tool, you need to know what is critical in your environment and think about how exactly you should monitor and treat it. If you have done that, everything will work just fine.
Well Suited - Networking Monitoring
Less Appropriate - When you need to customize some monitoring and to update the version
I recommend Splunk on-call is more suited where there are high incident queues; multiple teams need to be involved in handling a P1 severity issue. Multiple levels of escalation are needed environment where automated action is required. I recommend the solution for large-scale & medium-scale business units. For small-scale business units, I see the functional value is less.
VictorOps support has proven excellent for us. Because it is such a widely used tool, there is a lot of documentation on usage, and a large community of users to lean on. Also, many engineers have had experience working with VictorOps already, and the tool is so easy to setup / manage that much support isn't really necessary.
Other tools I have used are more server/application-centric. CA Spectrum seems to work effectively and efficiently for network devices. Notification delays can be set to grant grace periods in case of network blips or false positives, which occur ALL the time. Other monitoring tools send event notifications immediately and would clear instantly, which while on-call can wake a technician for no reason.
Splunk On-Call integrates better with our Splunk Cybersecurity and Reporting products due to the same family tree of the same eco system. We were previously using built-in on-call from individual applications and while adequate, they were difficult to manage and support SLA varied greatly across different applications. In addition we also used xMatters which did not integrate well with SAP products nor Citrix products so we were still using more than a single on-call product which was solved by implementing Splunk On-Call