single point of failure in IIS Web Farm Framework setting?

Question

• ASP.NET WEB API
• Windows Server 2008 R2/IIS 7.5/Web Farm Framework 2.5

I am planning to deploy application across 4 web servers.

Should i use shared content/configuration using DFS among web servers for web farm scenario?

Second option is to use Web Farm Framework for deployment.

Furthermore, is there chance of single point of failure in WFF? for example what if primary server goes down.

which option would be better? pros and cons of each of the above.

I will appreciate your response.