[Epic 4G Q&A, Help & Troubleshooting] Catalyst Shift:
This is a guide I’ve put together from my (in)experience with flashing ACS. It mainly comes from the replies of k0nane and theimpaler747 in the SyndicateROM thread. However, since there’s so many pages that can be tricky to search for idiots like me who just throw up random posts for others to solve their problems, I thought it would be good to summarize it along with anything I happened to notice from flashing a couple of Epics. Consider it the FIBI guide.

Step 1: Read all posts by k0nane on page 1 of the SyndicateROM thread before doing a damn thing! http://xdaforums.com/showthread.php?t=976194

Instructions for CWM are in this thread: http://xdaforums.com/showthread.php?t=897612

Useful hotkeys:

Download mode - Hold down 1 on the keyboard when you power on the phone

Recovery mode - Hold Volume down+camera+power to power on the phone

Reset phone - Hold volume up+camera+power. This generally works when the phone is completely locked up.

Flashing:

When going between versions of ACS, check their notes to see if you need to do anything other than flash. You can go between some versions without wiping or losing anything. You can also flash between standard and fully loaded without wiping or losing anything.

Sdcard doesn’t mount in CWM, but shows up in Android - Format the sdcard in Android.

Boot hangs on the Samsung screen – Redownload, format your SD card and reflash

Boot screen flashed between different things – Wipe cache & data 3x and reflash

Journaling:

Enable journaling – In CWM, go to backup and restore. Backup, then restore using that backup. Journaling enabled!

Make it so you don’t need journaling – Keep a copy of the ROM on your phone at all times. Should you ever have data corruption, jump into CWM and flash the ROM again. It’s quick, no wipes needed.

If you restore a backup made in CWM and want to have non-journaled again – Flash the ROM after restoring.

Other issues:

FC in a specific app – Go into manage applications and clear data for that app

FC in several apps – In CWM > Advanced, try fixing permissions. Can also clear caches, and if that doesn’t work, reflash the ROM.

If you have any major issues that seem unresolved, Odin everything back to stock with EB13, format your sdcard in android, re-download everything, re-install CWM, re-read all of k0nane’s posts on page 1 and try again.

If you want ads back – Install adfree from market and hit revert

If your phone is freezing often - Flash either the vision kernel found here: http://xdaforums.com/showthread.php?t=1012136 or the Twilight 1.0.4 kernel found here: http://xdaforums.com/showpost.php?p=12504067&postcount=5904. I haven't had the freezing issues, but I'd recommend trying the vision kernel first as it has some other potential benefits.

Recommended tweaks and add ons:

Fugutweaks – This will smooth out a few random things on the phone. I’ve noticed more responsiveness on the lock screen and icons on my homescreen. Small, but nice. Install the ZIP in CWM, file can be found here: http://xdaforums.com/showthread.php?t=981125

Impaled Keyboard – Makes the keyboard less likely to skip keys. Still have some, but they’ve gone down a lot. I use the Speed Demon Edition, still had a fair amount of dropped keys with standard one. Install the ZIP in CWM, file can be found here: http://xdaforums.com/showthread.php?t=1025533&page=18

SetCPU – Handles scaling the CPU and overclocking. Use ondemand setting for smooth performance. If you have issues when the phone is idle or it doesn’t wake up properly, set minimum CPU to 200Mhz. Free for XDA members, APK can be found here: http://xdaforums.com/showthread.php?t=505419

Battery Calibration – If you want to calibrate your battery without going into CWM, grab the app from this thread: http://xdaforums.com/showthread.php?t=1024867. It’s now available from the Android Market.

Vision Kernel – Pretty much Twilight + gives you 1.4Ghz and Voodoo colour which improves balance when brightness is at 100%. Flash in CWM, wipe dalvik. Kernel can be found here: http://xdaforums.com/showthread.php?t=1012136

And a final note that I'm now about 10 hours into testing... if you are using fully loaded and want better battery life, really try standard. It very easy to switch, it flashes over fully loaded with no wipes or data loss, the only thing you lose is that it resets your homescreens. But really, this is day 1 of it for me and 10 hours in I'm at 62% battery remaining. Usually by this time I'd be around 20%.