There is definitely a difference between the comfort seat cushions and the AVS cushions as AVS has 2 inflatable air cushions on each side for the AVS. I think this is the difference in feel between Comfort and AVS. Below is some info I got that explains this better:

Four air cushions are integrated in the seat surface for the active seat. Two air cushions,
one on top of the other, are used in both the left and right seat halves.
The air cushions are inflated with air provided by the pump for lumbar-support adjustment.
A solenoid valve is integrated in the pump unit. The function of the solenoid valve
is to change over the air supply. This ensures that only one function (lumbar-support
adjustment or active seat) is ever executed.
A distributor module is used for inflating the air cushions. The seat module delivers power
to the distributor module as soon as the active seat is switched on.
The distributor module houses a motor, which drives an eccentric shaft. The rotation of
the eccentric shaft causes the air inlets to the seat cushions to open or close.
The seat cushions are alternately inflated or deflated, depending on the position of the
eccentric shaft. The air inlets are closed when the system is switched off and in the
breaks between inflation or deflation.
A switch contact is integrated in the distributor module to switch on the pump for lumbar
support adjustment. The rotation of the eccentric shaft actuates the contact, which thereby
signals activation to the seat module. The seat module switches on the pump for lumbar-
support adjustment and changes the solenoid valve to inflate the seat cushions.