Why Use Opendns servers when compared to ISP's DNS servers

This question would probably be in the minds of many people . Some people claim that their ISP's DNS servers are faster than opendns servers . Well it could be possible for some ISP's . Here's what i think on DNS servers and why i still use opendns servers :
Firstly , i think the best reason to use opendns servers is that its SECURE . Opendns servers are much more safer to use than any other DNS servers . I'm not sure if you still remember , but there was this major news few months back on how DNS servers could be hacked causing everybody using those DNS servers to become victims of major SCAM including loss of passwords,private information etc . In short , when these DNS servers are hacked , when you enter www.google.com in your browser , you dont go to the actual google website , the hacked DNS server takes you somewhere else , probably to a website full of spyware and virus. CLICK HERE to know more on that .
So the security part is clear . Now coming to the speed . Let's take my ISP's DNS server for example . I use BSNL , and their DNS servers which are shown in my router's page are 218.248.255.139 and 218.248.255.212 . Now when i used these DNS servers and tested it with doxpara.com i get a warning saying that im prone to attacks . So , proof that its not secure .
Now coming to speed , i pinged the primary DNS server of my ISP and of Opendns . Here's a screenshot of that :

Now from this , i guess you may be thinking that my ISP's DNS servers are much more faster than Opendns , because my ISP's DNS server has a much less response time compared to opendns . But still , why do people face issues with ISP's DNS servers? why does everything work well with opendns servers?
Well this has to do with the ip address which is returned by the DNS server for a particular domain . For example google.com is accessible from the following ips :

Name: google.com
Address: 74.125.45.100
Name: google.com
Address: 209.85.171.100
Name: google.com
Address: 74.125.67.100


Now depending on the DNS server , they may give any one of these ip addresses when you try loading google.com . Opendns servers gives the ip addresses of the fastest server among them which has the least response time , therefore making your browsing experience a lot better.

In some locations , pinging the opendns servers give a much less response time compared to their ISP's DNS servers , then i guess its a direct answer that opendns servers are much faster.