So PerfMatters and WP Rocket do a lot of similar things.
The people i see using both, are generally using WP Rocket for the Page Caching, and then PerfMatters to do the optimizations.
Considering both plugins have a lot of overlapping features, if both are to be used, then make sure ONLY one of them is doing a specific thing. eg. if PerfMatters is optimizing the CSS, then make sure WP Rocket isn’t.
But if you’re getting better scores with a plugin, then maybe its a good time to ditch it.
Note on page caching. If you’re server has it built in, then you may want to use that instead 🙂