What are the pros and cons of using an alternative DNS instead of the ISP DNS server?

I searched the web for answers, but I haven't found anything conclusive. What are the advantages/disadvantages of using an alternative DNS (for example, OpenDNS or Google DNS) as opposed to the default ISP DNS server?

• Open DNS has services related to their dns servers, such as phishing protection or parental controls, though you may have to sign up to configure them.

• Selecting a server with better response time can speed up browsing

• Open DNS now offers an encrypted DNS tool, which keeps anyone from seeing your DNS requests. No matter whose DNS servers you use, your ISP knows every webpage you visit, even if the webpage is SSL, the DNS request is not encrypted even though the connection to the website is SSL encrypted, so they came out with the tool to take care of that vulnerability.

So it can improve browsing speed and security, you may not get both depending on where you are.

some advantages:

• they can be more stable and not fall, when your provider fails

• they could be more trustfull (your provider could redirect those "not found" to an advertising page, while the openDNS or Google DNS say they don't do that)

• they could be faster (yes, your provider can be using a hardware that can't handle all the requests from their consumers)