I'm slowly moving all my websites to Gumlet. I've ran some comparison tests and it had the fastest CDN, which is why I decided to continue with Gumlet. In terms of image compression Gumlet performed slightly worse than ShortPixel, but the CDN was much faster so it made up for it.
In addition, Gumlet can also serve CSS and JS files, so I have no need for a regular CDN anymore.