Thanks Frog!
I applied the 'patch' to my existing game (xxlarge lush world from ecomental, Heavenfall's mod 7 AI, everything set to ridiculous, my custom sov), which was at turn 178. Turnset time was about the same for the few turns I played, but it seemed the in-turn unit movements, cursor movements, etc. were a bit 'jerky'. System is I7 920, GeForce gtx 260, win7 64bit, 6gb ram, raptor HD -- almost 4 years old.
I figure jumping into the middle of a game isn't a 'fair' test so I restarted that same game (used the very same starting savegame -- I save immediately upon creating a new game, before moving or doing anything), currently turn 147. Observations so far:
-turn times seem normal, no slowdowns, or jerkiness observed
-wandering mobs seem more active. Had 2 obsidian golems attack within a few turns of each other, in addition to the mobs that hit me in the pre-patch game. This has caused me to expand slower, and build more units for defense in the patched game.
-I met the frost giants a bit later in this game -- they were ~3x my score in the pre-patch game, in the patched game they're ~6x my score (in the first game they never exceeded 3x). In the first game all met AIs were ~3x my score so seeing the frosties 6x is heartening (and scary!)
-I noticed an angel champ sitting on a loot spot (library perhaps) and when it moved off next turn the library remained. I haven't tried to move onto this library to see if it's really still there or just an artifact, will try to do so when I can spare a champ
-an angel unit (melee, not angel scout) chased my scout, my scout moved past a strong mob sitting in its lair, angel unit moved adjacent to mob then stopped for at least 10 turns. The mob didn't attack the angel unit. I kept a unit within range to observe this for at least 5 turns, moved off, a bit later moved back and to within ~4 squares of the angel unit, then the angel unit started moving again. So the angel unit appears to have gotten 'stuck', and the mob didn't attack it.
-in the pre-parch game the frost giants were about a third of the map distance from me. They war dec'd me within a few turns of meeting, but never sent a stack at me (I kept a scout near their border in what I think is the only approach they can make) in over 50 turns.
-The angel faction is located fairly close to me. In the pre-patch game they were neutral, in the patched game they war dec'd me almost immediately and are hitting me very hard, with multiple stacks that are having no trouble finding my adjacent cities.
-Haven't noticed any strategic spells cast, but haven't moved into an AI territory yet
-Have noticed other AI taking each others' cities
So far, this patch improves things a lot, without much adverse affect (at least so far, 147 turns in).