Yes, they are different. Dynamic cruise is standard on all models (I think) and it's really just regular cruise. I think by "dynamic" they mean that it will brake to some degree going down hill to keep you at the selected speed, but it doesn't follow the speed of the vehicle in front of you like Active Cruise does. Active cruise is a very expensive option and I decided against it on my 335 for that reason. I think it's about $2400 USD. I think dynamic cruise will be good enough for me...

__________________
'08 335i Coupe - Barbera Red / Saddle Leather / Light Poplar Wood / 6spd Manual
Options: Sport, Premium, Cold Weather, Comfort Access, Active Steering (awesome!), Power Rear Shade, IPod Adapter, Navigation w/IDrive
Mods: M6 Wheels, Split Armrest, M-Steering Wheel, Euro Light Switch w/Rear Fog Lights, Short Shift Knob w/Matching E-Brake Handle, Clear Reflectors, CDV, Clear Bra

Retired:'04 X5 4.4i