Thanks everyone!
Simon, if you enter the BIOS (F2 on splash screen for me), you just have to poke around in there to find "Intel SpeedStep". In my case, turning it off helped the CPU not throttle down and cause pops and clicks. If you are not comfortable navigating the BIOS, be careful. It's easy to make bad mistakes in there...
The complete solution to my latency problems was to always do a fresh boot (no sleep mode), have those power settings set to "never", and be plugged in on AC not just the battery. I can't tell you how ACPI.sys wants to take over my system. These were the only steps that eliminate that problem for me. Not a huge deal, but one that almost makes me wish I had switched to a MacBook Pro...
Thanks,
David