480s i have the leather brown and pink ones, no heel slip for me, however I agree on the stability issue others expressed. if i put anything thicker than the stock insole in them i feel like I'm gonna fall over just walking through the living room. I have not skated them for this reason. I do feel like there is more cushion in the heel on these than the 1010, could just be the heel to toe drop being a bit different though.
I've had 2 pair of 1010, the first was the caramel/tan with blue mesh and other is the green with leather toe area, the green pair had very little heel slip, after a day it went away, the caramel ones i had to heel lock the laces for like 2 weeks but then it also went away.
1010 size 11 and the 480 size 10.5