Two weeks ago or so I got a lovely new laptop, the HP Elitebook 2530p, but quickly found that ACPI on it would make it hang at boot. I installed with acpi=off, and used it as a desktop-style testing machine while we tried to figure out what was going wrong with it. It was kind of rough, as someone who's never debugged ACPI before -- the googling gives you documentation that advertises itself as stale (so why does it exist?), and the real documentation isn't where it should be. The ACPI guys I know seemed stumped -- various debug output all came up clean, yet enabling ACPI caused boot-time hangs in the ACPI battery, ACPI thermal, and HDA drivers.
It turned out after I nuked a bunch of BIOS options, that the option to enable the fan while AC is on is what was causing it. Disable it for linux on 2530p happiness.
Also, suspend/resume works out of the box, as long as your box includes loading the Intel DRM.