Switched to nginx
I have been able to move all my public virtual hosts, and have already noticed the improvement on how fast the pages load. Here is a sample graph of the disk I/O rates of my linode showing before/after the switch to nginx:
For now, I keep apache running for the DSPAM Web UI, which requires suexec. I know I can easily run the CGI through a different user, but still have to polish my setup for FastCGI.