I did some more testing with my G.Skill HZ today. I only cared about max screenshots, so with that goal in mind here is the test system:

A64 3500+ Venice
DFI LP NF4 Ultra-D (623-3 bios)
2GB G.Skill pc4000 HZ 2.68v, dual-channel, crowded but actively cooled
480watt Antec Neopower PSU

I've never removed the heatspreaders, but my ram is from the batch that shipped with timings of 3-5-5-10.

Here are the results:

ddr510.1 @ 2.5-3-3-5 1T
[img=http://img89.imageshack.us/img89/7492/ram4yj.th.jpg]

ddr540.4 @ 3-3-3-5 1T
[img=http://img403.imageshack.us/img403/4232/ram39xp.th.jpg]

ddr587.4 @ 3-4-3-5 1T
[img=http://img403.imageshack.us/img403/6025/ram46cw.th.jpg]

ddr600.92 @ 3-4-4-8 1T
[img=http://img403.imageshack.us/img403/5174/ram55nh.th.jpg]