Actually sometimes it makes the load more slower. I mean, is obvious because you have CF on the middle of the request which means that all the non static content has this in the middle.
CF is good for two things: Serve static content (images, css, etc) and DDOS mitigation. If you run the free version you will mostly avoid any layer 7 ddos attack and if your website has a lot of static traffic you will save a lot of bw for free. Now, the ddos mitigation works as expected on the business plan (Im actually using that plan) but is not the real thing... They dont even say to wich attacks you will be protected and the quotas doesnt exists so is like a shared ddos mitigation.
My recommendation? Use it only for static traffic. If you need ddos protection get the real thing which by the way is often way more expensive than 200 USD... And use Litespeed server ofcourse.