[Vibrant Android Development] ebullient:
It's not a script. Samsung uses a proprietary filesystem called RFS which is slow, Voodoo replaces it completely with EXT4 which is fast. I'm oversimplifying, for more details go here: http://xdaforums.com/showthread.php?t=799931

In real-world use, SGS' hardware is so awesome you hardly notice. If you're using multiple apps at a time, you will notice (example: writing and sending an email at the same time you receive a text message, your email can hang until the text message is finished). Personally, the Voodoo lag fix screams compared to stock.

There is a tradeoff. If you yank the battery out before you save and close a file you were working on, chances are good you'll lose your data (who does that anyway).

For those hesitant about using the lagfix:

Short answer: don't.

Long answer: do! And don't be scared! I admit, the ability of people to not follow very simple instructions is amazing but if you follow sombionix' instructions, or any of a number of instructions that have been posted in this thread, you'll be fine! Let me explain what the deal is here.

When Voodoo is enabled it is using a different filesystem which messes with flashing. When you disable Voodoo it converts the filesystem back to normal so you can flash safely. Voodoo is easy to enable/disable by using a 'switch', simply a blank file with a filename that Voodoo looks for when shutting down/booting. You change the name of this file to the name Voodoo expects, Voodoo disables itself when you power down and will stay disabled when you boot. You change it to ANYTHING else, Voodoo will enable itself when you boot.

Here is my simple solution to switching Voodoo off and on:

First, setup your 'switch.' This assumes that you have just flashed your first Voodoo build which is safe to do if you have never flashed Voodoo before.

Mount your internal SD card. Unless you've changed things, this is the drive that has the 'Android' directory on it.

Find the 'Voodoo' directory. This was created for you when you flashed Voodoo. If you don't have it, go ahead and make it and check the OP for instructions on how to make sure that you really did install Voodoo.

Inside this directory make a blank text document. The contents of this file are unimportant, still leave it empty but Voodoo does not care what this file contains as it is only looking for the filename.

Name the document something random like 'renamedis' or 'voodooison'. Don't name it 'disable-lagfix' yet! I will outline a routine for flashing next.

Exit, unmount drive. Your switch is now in place!

Now, before you flash ANYTHING, perform the following:

On your phone, use 'Files' to browse to your internal sd card. Once again, this is the card with the 'Android' directory on it unless you've changed things.

Open your 'Voodoo' directory.

Long press the 'switch' you made. It will be whatever you named it above and it might have .txt at the end.

In the menu that pops up, select 'Rename'.

Rename the file 'disable-lagfix'. Completely erase the original name and manually type it out. Make sure that it is exactly 'disable-lagfix' with no .txt at the end and no quotes.

Shut down your phone. If you did it right, an electronic female voice will start telling you what Voodoo is doing to disable itself (note that this is NOT the bionix voice saying 'initiating countdown', it will say something about a partition). If you wait several minutes and you hear no electronic female voice then you did something wrong. That's ok, you haven't broken anything! Just power back up and try again. If you're not plugged in, Voodoo will disable on boot and you'll hear Linda (the voice) then.

After finishing your flash, either name the file something else or move it somewhere else. Don't delete it as you cannot make blank files from Android.

I recommend doing this while you're plugged in. The battery charge indicator will be gray with a busy icon while Voodoo is shutting itself down. Once Voodoo is done, the battery indicator will go to its green charge bar. That way you know Voodoo is finished and it's safe to boot. If you messed something up and don't hear an electronic female voice, then once the battery goes to its green charge bar, you know its safe to boot.

The female voice works regardless of your volume settings (don't do this during a meeting).

Volume is quieter in JI6 due to volume compliance issues in Europe. Or at least that's the rumor I heard.

Personally, quieter is better. The earbuds I want to use are too loud on the lowest audible setting.

I am also having this issue. I'm going to try reflashing and a few other things. Did all your bloatware come back too?