Is Cloudflare Recommended?

Is Cloudflare recommended for use to speed up website and increase security? Because I have seen many posts in this forum that order don't get placed successfully and also conversions go down? Is that true?

We didn't realize any issues with them in the past years.

Just be careful given that free versions of cloudfare do NOT use SSL between the cloudfare servers and your site. Only connections to cloudfare IP addresses are secured via ssl.