Code:
1. Boot, HBoot and Radio same in all. Recovery, system & userdata different in each.

2. Facebook - Same in EPE54B & EPE68. Different in EPE76
3. No GoogleGoggles.apk in EPE68 & EPE76
4. No googlevoice.apk in EPE68 & EPE76
5. No VoiceDialer.apk in EPE68 & EPE76
6. MMS app has some mms_config xml changes, some new ones added. EPE68 has more.

7. More APNs in EPE68 & EPE76. Specifically European APNs.

8. framework-res.apk same in EPE68 & EPE76. Language resource changes from EPE54B.
9. Framework odex file almost identical. Only 3 consistent hex chars difference between each ROM. Essentially means no framework changes.
10. Firmware modules same. Kernel same. Baseband same.

11. EPE68 & EPE76 are configured to look at the Europe NTP pool
13. EPE68 & EPE76 product name changed from passion to passion_eu
14. EPE68 & EPE76 locale region default is GB
15. EPE68 & EPE76 build descriptions start with passion_eu-user 2.1-update1
16. EPE68 & EPE76 build fingerprint start with google/passion_eu/passion/mahimahi:2.1-update1

http://forum.xda-developers.com/showthread.php?t=648856