Its my first post on these forums, so I would like to say 'Hi' to everyone.
I only hope that person that will be doing these tests will read this post, since this thread/comments grown very big.
1. HARDWARE
Many people scream to use ATI or nVidia cards, but AMD does not provide their drivers to NetBSD and FreeBSD, nVdidia only provides i386 driver for FreeBSD, but there is no amd64 version, and no version for NetBSD either.
The only graphics card, that will made all these tests equal for all systems is Intel based integrated card, and a little older one, not the newest one.
For laptop tests (if there will be any) best chioce will be X3100 or GMA 950.
For Desktop tests best would BE GMA 3100 for example.
2. VERSIONS
If you will not include FreeBSD 8.0 (will be released in middle September) tests will not be fair since its one of the biggest FreeBSD releases ever, or at least include tests for 8.0-RC* versions.
I would also include these systems:
NetBSD 5.0.1
Ubuntu 9.04
CentOS 5.3
Mac OS X 10.6
OpenSolaris 2009.06
3. SERVICES/FEATURES
FreeBSD and NetBSD comes as a BARE MINIMAL systems where you can add everything by yourself, Mac OS X, Ubuntu and OpenSolaris comes with all features and services by default, so be sure to disable many features and compare Oranges to Oranges, not Apples to Oranges ...