[Captivate Android Development] GGXtreme:
Well, I don't know if I answered my own question, but while this appeared to work just fine at first, I now get sleep death 100% of the time when phone is charging and screen turns off. My uv settings are very mild (1200/0, 1000/0, 800/25, 400/25, 200/50, 100/50). Not sure if SetCPU has anything to do with this (only profile I'm using is 'Screen Off' to cap CPU at 400MHz). I passed 30 rounds of stability testing, as well as other stress tests and benchmarks without a hitch.

Edit: Hmm, alright, I believe I've solved all my issues. I didn't even notice at first that the voltage for lower clock speeds was lower to begin with, so I removed all undervolts for 400MHz and under (where I usually set my screen-off profile in SetCPU) which fixed my charge death and allowed me to bump my undervolt settings for higher clocks.

Then I created a text file containing all my enabled states in KHz from low to high (separate by commas, ie. "100000,200000,400000,800000,1000000,1200000") and saved it on the root of my SD card as 'setcpu.txt'. I went into SetCPU and chose "Show other frequency sets", then scrolled down to the last option for custom frequencies and selected it. SetCPU then loaded all the states enabled in Voltage Control. I changed the scaling from 'ondemand' to 'conservative' and re-added my profiles.

Instantly, everything is much smoother. I can safely turn off my screen with no sleep death or charge death.

Hitting 16.611 in linpack (about the same as #53-1000Hz, Speedmod gave me 13-14) and between 1350 and 1450 in Quadrant (same as #53-1000Hz and Speedmod). SetCPU benchmarks are insane (150-160ms for short, 460-470ms for long; didn't test with #53, Speedmod gave me 170-180ms for short, 500-600ms for long). Compared to #53, it seems that #54 is somewhat smoother and more fluid in the UI and such, but I've noticed a large drop in 2D and 3D performance benchmarks (in #53-1000Hz, I was getting between 55 and 65fps in almost all benchmarks including An3DBenchmark and getting arbitrary scores of over 8000, which is very high for the Captivate; in #54-1000Hz, I'm getting about 10fps less in everything and scores between 5500-6500). Also, LauncherPro now FC's for me every time it loads on boot (even if I let it load fully), but works fine after it reloads. RL sqlite is giving me about 62 seconds now (#53-1000Hz gave me about 66 seconds, Speedmod gave me about 53 seconds, which is significantly faster for database read/write). SmartBench 2011 is giving me really low scores, rating me lower than a stock Captivate. Compared to Speedmod, I found the UI more jumpy in #53 (faster but seemed to run into hitches and occasionally freezes requiring a reboot), #54 and my SetCPU tweaks seem to have resolved this. GameBoid is running noticeably smoother compared to Speedmod (less frameskipping and more fluid audio), but I've notice audio getting out of sync a lot, which never happened on Speedmod. My ROM's shutdown animation is also completely smooth now (it was always jerky with Speedmod). I haven't had time to test out battery life, but I expect my SetCPU settings to improve upon whatever this ROM already has to offer.

I honestly don't care much for oc/uv, but I don't mind a bit of extra speed while on the charger, and seeing that Speedmod is pretty much at the stages of what I would say is 'Final', I wanted to give this a try since it still has it's own updates going on. Hoping to see more of this kernel in the future.