but your alpine unit wont give you;
cruise control diallights, comes with instrument cluster with large MFD (bluetooth option/retrofit)
low washer fluid warnings, comes with winter pack / Xenon option, or can be retrofitted.
door/boot open indications, on the larger MFD
the fascility to change comfort options, on the larger MFD, (more options on MY07 cars or later)
last caller details, large MFD
missed caller details, large MFD
sat nav directions, large MFD
cd track details, large MFD - only shows track number
low tyre pressure warning standard feature
etc, etc.
so much more than bluetooth....