Is Jetpack Photon image CDN is good enough ?

IS Jetpacks Photon image CDN is good enough ? I have enabled it on my website and i can see images come from i2.wp.com
Now when Anyone visits my website and views the images Do those images NOT use my website’s server’s bandwidth and resources. Can i go ahead and upload as many images as i want on my website and not worry about high cpu and resource usage because I am on shared hosting and i upload most images on other website like flicker photobucket to keep server cpu usage low because the traffic is high on the website.