Pros:
A completely open source build making it very versatile and well supported.
High level of encryption (1024bit).
If your VPN connection is severed (logout/disconnect), then your network stops until you log back in or turn off OpenVPN.
Cons:
Complex and lengthy setup process for new users.
More overhead due to higher encryption.
Blocked by strict proxies (i.e. work, school, open networks, etc...).