I certainly haven't noticed any real-world degradation in using OpenBSD on my servers as opposed to Linux. And OpenBSD may not be as advanced as FreeBSD in that department.
In real-world use, I would be busy trying to ensure that my Linux boxes had the latest security patches, and after upgrading my libs for the nth time, I would be in the midst of tracking down weird issues with binaries using those shared libs.
In the real-world, if a customer had a problem, I would just buy them an Athlon and load them up with RAM and RAID.
