I turned it on and actually forgot I did. Performance is decent here. I mean of course it's going to be worse than native, but that's the compromise.
As to trusting Cloudflare -- what do you mean? You understand your connection is still TLS end-to-end encrypted (presuming that's what we're talking about), right? I mean...presuming the site your talking to isn't using Cloudflare SSL. In no way does this reduce that security. If you're talking about HTTP, well everyone in between can already see that.