I found the setup and configuration of OpenVPN to be very easy and straight forward. Much easier than setting up IPSec for sure. It was as easy as doing a yum install openvpn then editing the configuration file to fit my needs. One thing I also installed was the OpenVPN Webmin module. The way I use Webmin is to set it up to use SSL after installing it. Then I run it once I log in via SSH to a server. That way it is not running continuously, nor do I keep it on the default port of 10000.
Once the server is configured it is quite easy using the Webmin module to create a CA (Certificate Authority) and generate certs. Another function the module does well is generate a zip file with the needed keys and a client config file for the user you create. This makes is easy to maintain a large list of VPN users. Some clients I use in our environment:
I have found from testing that even with the use of 2048bit keys performance is very good. By forcing users connected to use our internal DNS servers people can access our intranet sites easily from anywhere.