I remember this from a while back:

https://news.ycombinator.com/item?id=12158174

&&

https://techcrunch.com/2016/07/25/security-as-a-service-star...

I have no experience with the Stackpath CDN itself, but I can only guess it's exactly like MaxCDN, which are apparently the cheapest and fastest. All these CDNs are more or less the same in terms of speed and availability though. Since it's such a competitive space, I don't really mind what CDN I use, as long as it's cheap compared to others and it has a decent amount of PoPs (Point of presence) scattered around the globe.