1. Optimum:
Best in terms of regular usage performance versus battery saving.
Usage: Ideal profile
Max: 805MHz
Min: 500MHz
Idle: 0 - 500 MHz Starving
SR VDD 1: Enabled
SR VDD 2: Enabled

2. Blood Kain
Performance boosted beyond limits, with much effort put in to issue reasonable usage of battery juice.
Usage: ULV
Max: 1150
Min: 500
Idle: 0 - 500 Starving
SR VDD 1: Disabled
SR VDD 2: Enabled

3. Life Doubler
Best in terms of power saving. Day-to-day performance is very good too.
Usage: ULV
Max: 750
Min: 500
Idle: 0 - 500 Starving
SR VDD 1: Enabled
SR VDD 2: Enabled

4. HD-Optimum:
Best choice if your using 720p DSP libraried installed, I personally use this.
Usage: Custom
Max: 900
Min: 500
Idle: 0 - 500 Starving
DSP: 600MHz
SR VDD 1: Disabled
SR VDD 2: Enabled

5. HD-Blood Kain
Turns your N900 to a Nuclear Power Plant.
Usage: Custom
Max: 1150
Min: 500
Idle: 0 - 500 Starving
DSP: 600MHz
SR VDD 1: Disabled
SR VDD 2: Enabled

6. HD-Life Doubler
Even though playing HD videos requires lots of power, this profile manages to get the most out of your battery.
Usage: Custom
Max: 805
Min: 500
Idle: 0 - 500 Starving
DSP: 600MHz
SR VDD 1: Enabled
SR VDD 2: Enabled

In all of these profiles, the vfs_cache_pressure is set to 10 when the device is idle and 100 when it is in use. The processer is also set to an ultra low power state (starving), and the usage of process SIGSTOP pauses greed processes when idle such as trackerd to drastically improve battery usage.