I use them. DD is 14 months and they are still in. She has never tried to use them to escape the crib. I don't mind changing the sheets with them. I don't think they make changing the sheets harder. DD is also a mover and I was worried about her getting her limbs caught. When DD was 4 months we were at a hotel and the loaner crib did not come with a bumper. And DD woke up CONSTANTLY from banging herself against the rails.
SIDS is unexplained death - there is no cause. And I don't really see how a baby that can't roll over can suffocate on bumpers. When they are newborns they don't move much in their sleep.