You do. You're thinking of the rollover protection system which is something completely different.
There's no labeling or anything that identifies it as AHR. It's just standard and only on the front seats. You can tell the difference with pre-09 cars because the AHR do not have stitching on the headrest and you will not be able to manually tilt them or completely remove them.
As far as how high, I think they just move the same amount from whatever height you have them set at.
AW/Terra | ZSP | ZPP | ZCW | iDrive | CA
Mods: BC BR coilovers | Blacklines | M-tech rear | dual exhaust | M3 steering wheel | BMW SSK | ZHP shift knob | High-kick CF spoiler | NBT Retrofit
M3 front control arms | M3 rear guide rods | Manzo rear toe and camber links | Monroe rear shock mounts | Varrstoen ES1 19x9.5+20 Front, 19x11+25 rear