Verizon DNS slow

I have Verizon FIOS (in MA) and I have been using Verizon's DNS servers. Sometimes, they seem completely unresponsive for large blocks of time (~30min).

I recently switched to OpenDNS servers and so far it seems much more responsive. Will report back later.

old Verizon DNS servers: 

71.243.0.12
71.250.0.12

new OpenDNS servers:

208.67.222.222
208.67.220.220

Note: changing the DNS server settings in the Verizon router required some hunting. I ultimately changed it by going through the following links: My Network -> Network Connections -> Edit Broadband Connection -> Settings -> DNS Server: Use the Following DNS Server Addresses

UPDATE: Connection still slow. Switched to Google DNS to see if that helps.

8.8.8.8
8.8.4.4