"RE: (Late 2008) MacBook Pro EFI Update 2.8 (display flicker fix)
   The EFI update works as promised. I am at 23 hours of having a flicker free display while running either the 9400 or 9600 gpus.
   Also, whatever was corrected/adjusted in the update also seems to have had the unanticipated side benefit of restoring battery life. (? I asked if he'd report back on this after more use. Maybe the equiv of a SMC reset helped. Unless there's other chgs/fixes apple didn't mention.)
   Before I was fortunate to get an hour of light use (for example: web surfing on Safari w/o Java or Flash plugins installed and only 1 or 2 windows open and only default OS X background activity) with a 4 month old battery before I was forced to reconnect my power adapter. Last night, after running the update, it took 2 and a half hours of watching movies in DVD Player using the 9400 gnu to kill the battery. After a recalibration, OS X is reporting a battery life of 4 hours as I type this email with Safari active with 10 open windows, Mail and iTunes downloading a 10gb library from iCloud.

Considering that I bought this system last July for the low, low price of $50, ($50? that's a steal ) I had been considering it a excellent purchase, even with the screen flicker. But as of today, I definitely feel that way!

(On March 19th he sent a follow-up after more use)
It is day 19.... Still have not had any problems with screen flicker returning. Battery life is holding firm between 2 and a half to almost 4 hours of life, depending on what I am doing. I even manage to get almost 2 hours of life when running skype on the battery. I am satisfied.
-Joel"

Anyone else notice any effect on battery runtime? (not checked apple's forums)
  

"About iMac Graphic FW Update 3.0
This firmware update fixes a graphics issue that may cause an iMac to hang under certain conditions. Do not shut off the power on your iMac during this update. Loss of power could result in your iMac failing to start up.
System Requirements: OS X Lion"

As before, the D/L page doesn't mention the specific iMac series/year. This same update (title and description) was originally released on August 24th, 2011 for 21.5in Mid-2011 iMacs (per the original installer script check).
   Our August 24th, 2011 News post on the original release noted the installer script (at that time) checked for "iMac 12,1" (Mid-2011, 21.5in IIRC), a specific OS X 10.7 build (10.7 build 11A511) and iMac Graphics ROM version (113-C2950K-193) - so my guess is Apple revised the installer to work with later builds in case there was any old stock out there with that ROM version. And I noticed the Intel-based iMac updates lists it under "Late 2011" iMacs now. (If someone checks the pkg contents/scripts to find any other changes, send a note. If it was really a new firmware update it should have had a later update number.)
  

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