true difference between alltel and sprint roms

[zeurx]

so i was unpacking both the sprint and alltel roms when i noticed the version information in pkgtools
Alltel:

[Selected Path]
  C:\Users\Administrator\Downloads\Pocket PC\Development\ROMS\2.14.671 Alltel\dump

[Core OS]
  Windows Mobile-based Pocket PCs

[Versions]
  SYS: 5.2.17740.200
  OEM: 19.6.0.671
  OEM: 19.4.0.671
  SYS: 5.2.17745.203
  NET: 2.0.7045.0
  OEM: 19.2.12101.671
  OEM: 19.3.12101.671

[Language]
  0409 - English (United States)

[DPI]
  96

[Certificates]
  CN=Microsoft Windows Mobile PCA, O=Microsoft Corporation, L=Redmond, S=Washington, C=US
  CN=OEM Sign 2005
  CN=OEM_UpdateCert
  CN=Operator_Test

[Missing Manifests]
  d92a4f0a-378a-4482-8fd3-bd127a05e4de.dsm
  723fb954-d931-4348-b672-82a188e587b5.dsm
  3174b293-abb8-d934-b13c-77f0d46081c2.dsm

sprint:

[Selected Path]
  C:\Users\Administrator\Downloads\Pocket PC\Development\ROMS\2.17.651 Sprint\dump

[Core OS]
  Windows Mobile-based Pocket PCs

[Versions]
  SYS: 5.2.17740.200
  OEM: 19.6.0.651
  OEM: 19.4.0.651
  SYS: 5.2.17745.203
  NET: 2.0.7045.0
  OEM: 19.2.12101.651
  OEM: 19.3.12101.651

[Language]
  0409 - English (United States)

[DPI]
  96

[Certificates]
  CN=Microsoft Windows Mobile PCA, O=Microsoft Corporation, L=Redmond, S=Washington, C=US
  CN=OEM Sign 2005
  CN=OEM_UpdateCert
  CN=SPCS_001

[Missing Manifests]
  d92a4f0a-378a-4482-8fd3-bd127a05e4de.dsm
  723fb954-d931-4348-b672-82a188e587b5.dsm
  3174b293-abb8-d934-b13c-77f0d46081c2.dsm

as you can see the version information is the same. my question is how different are the base system of these roms, or is it all customizations from the carriers?