The SMP suite is great at what it does, but it can be very complicated to learn how to get it to do what you want. It's a beast! However, when you learn how to the things you want to do, it comes as second nature and you complete them like they're supposed to be done that way. A lot of these things are done to be able to be completed a number of different ways. Take Patch Management, you can deploy patches automatically, via Jobs, or via the "Start Software Update Cycle Now" link in the SMP Agent!
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.
The SMP solution is a beast. Each piece is complicated in itself let alone how everything ties together!
There is plenty of documentation online on how to perform a specific task, but you need to pay attention to what VERSION the article is written for. I've been halfway through implementing something only to hit a roadblock since I'm running a newer version and the option the article says to click on doesn't exist anymore...
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.
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
Being able to report on the majority of things you want all from one interface, makes it really easy to get the results you want.
Because my employer didn't provide training, it took working with support, reading technical documentation, and just playing around on my own to learn how to do certain things.
I've had a lot of help from the SMP Support staff and they're great people and very helpful!