MapifyPro is a responsive UI plugin. Hence, it's very fast.
Real-world performance depends only on the internet speed of your site visitors. If they have a low-end CPU and if you have a large number of Maps, that could potentially be a limiting issue, however we have had no complaints from customers.
We have customers with thousands of Map Locations on a Map. One helpful tip is to enable Clustering so that Map Locations that are grouped together will appear as a single clustered pin. This ensures high performance even on low-end CPUs.