In reply to Vampirov:
Its hard to say the Activ probably is a bit wider where the little toe is on the footbed, but because the toe box/front of boot is less high/baggy the sides of the boot are more supportive, plus the (masses of!) foam inside helps things, but is a bit warm in summer!
I think the activs have a more pronounced rocker and are definately more bendy (and comfy) out of the box than the M3. Not sure what a toe spring is :-/