[Captivate General] patrokov:
Just sharing my experience in upgrading to Jelly Bean on the Captivate.

Before you begin:

Before you begin, back up your efs partition.

Some ICS and JB ROMS have issues where they will forget your IMEI. If this is the case you'll need to restore your efs partition. If you don't already have a back up, you'll have to reflash to stock (pain in the butt) so that you can back up your efs so that you can restore it on your shiny new ROM. Without an IMEI, you won't be able to make calls or access wireless networks.

How to Backup/restore EFS: http://xdaforums.com/showthread.php?t=859914

General Process

ICS and Jelly Bean are too big to put the entire rom in /system, so the current practice is to break up the ROM into 2 or more zip files (the ROM itself and a second zip that has essential apps like the Market). Both have to be flashed.

The ROMs have upgraded CWM (Recovery Modules) so you have to flash the ROM twice. The first time installs the CWM, the second time installs the ROM.

My journey

I had been using Mosaic, which is now defunct. When I started seeing posts from Studacris (former Mosaic developer) from several months ago saying "Gingerbread? What is this the stone age?" I decided perhaps is was time to upgrade to ICS.

Of course when I started looking at ICS ROMS, it turns out that now there are Jelly Bean ROMS available as well. Some people say the JB ROMS solve several problems with ICS. Others say the ICS are more stable for now.

Moral of the story. Your Captivate is unique. You won't know which is which until you try them, but my journey may help you.

1. I want to try Slim Bean, but coming from Gingerbread, it's recommended to start on Cynanogen (CM)

2. So I might as well try CM, but do I try CM9 (ICS) or CM10 (JB)?

3. Ah what the heck, let's go CM10!!!

4. Okay, there's at least four versions. The official, three unofficials of varying "v" releases, the Devil version with datadata (what the heck is datadata?), some guy's custom rolled ROM which he says is likely to brick your phone.

5. Okay, I'll try the latest V8 version with the Devil kernel (note, you should use the version with datadata).

6. Flash goes fine, but now it hangs on black screen with the word Android. After 30 minutes, I figured it really was hanged. Reflashing and rewiping solved that problem.

7. I had a lot of issues with it (see below), so I decided to try Slim ICS.

8. I had other issues with SlimICS (see below), so what the heck, let's try Slim Bean.

9. Slim Bean seems like a keeper to me: Fast; great feautures; decent launcher (vastly better than SlimICS). Only real problem I'm finding is that the Market won't let me install (or even see) Astro Player, which is one of my absolute must have apps. Still trying the dev's workaround.

CM 10 Issues:

Outdated:

1. The home key and back key are reversed.

2. My IMEI was wrong, and restoring EFS didn't help

3. I experienced intermittent lag on the launcher

Update CM10

Everything works fine in CM10 Helly Bean (29.07.2012). Faster than Slim.

http://xdaforums.com/showthread.php?t=1783064.

Slim ICS Issues

The first thing the Slim ICS installer does is install its own CWM and in the process it will erase your sdcard (internal memory)

SO....

1. Back up your internal SDCARD before you start

2. To save time, put the zip files on your external card also (the newer CWM will let you install from the external card)

3. I hate the launcher

4. I still couldn't make phone calls.

Slim Bean issues

Works great except for the market issue. Seems to be a problem with the DPI. Still waiting to see if it resolves. Alternatively, I could try to restore my Mosaic version of Astro Player with Titanium back up.

Update:

1. Market issue resolved after about 36 hours of following the fix on the website.

2. Internal card and sdcard were reversed, (/sdcard and /emmc)

Conclusion

I hope my journey helps someone out there.