This is my review on using the cloudflare for"FREE" if you are using premium subscription you can make a reply below with full details.
PROS:
Threat control:
There is a three layer threat control available in cloudflare
1. Low -automated bots will be stopped automatically
2.Medium- Bots and the spammers which are recgonised all over the internet cant access your site
3.High -all bots and crawlers will be stopped even google,msn,yahoo
or you can have a custom setting
Performance
This also have three levels
apart from the three levels you can minigy your sites css html and java scripts
1.CDN only
This has simplified caching (reduced load for your server)
cache stays on for 4 hours on your users computer
Rocket LoaderBeta
Automatically asynchronously load all JavaScript resources.
2.CDN + basic
caching aggressive ,faster loading of site, and has few other perks
3.CDN+Full
has all the things of the above too and you get an zero downtime and reduced page load timings
CONS:
The major cons are two
1. server load:
your server load will be increased based on the level of the performance you use
2.adsense or any other ads
your ads will disappear from your site if you choose to high threat level
ofcourse you can add exceptions to your settings.