I recently upgraded the hard drive on my mid-2009 15" MacBook Pro, from the stock 250 GB/5400rpm Hitachi to the Western Digital Scorpio Black 750GB/7200rpm. (see original post here: http://forums.macrumors.com/showthread.php?t=1346126) Prior to this new hard dive, I had the EFI 1.7 firmware and my original stock drive was absolutely flawless. Fast, reliable--the only reason for my upgrade was merely for more space. After installing the new hard drive, my initial boot took much longer than usual. I had read this was normal so didn't think much about it. Once I was fully started up, however, my computer was SUPER SUPER slow. Like, every click, opening of a folder, typing into a input box, etc. caused endless beachballs and lagging. I looked up the issue (using my iPhone since my computer was pretty much useless) and found that some slowness was to be expected as Spotlight would be reindexing my drive. So I left my computer running, came back in a few hours, and checked my Activity Monitor to confirm Spotlight was no longer indexing. Still extremely, painfully slow. Repairing permissions, resetting PRAM, etc. did absolutely nothing. Further research then brought me to the issue of the mid-2009 Unibodys with the 3.0 (see: here and here). I followed the makeshift solution, which was to downgrade from EFI 1.7 to 1.6 (instructions here) and THANK GOD. My computer is now super fast and operating as normal. No more beachballs or lagging (knock on wood). Now my question is, this issue apparently has been going on since 2009. I only just experienced it now because it was my first time upgraded my hard drive. Have there been any new developments or am I destined to live with EFI 1.6 forever? I'm just afraid that the downgrading fix is just a temporary solution and won't be stable in the long run in terms of capability with the hard drive mechanism.