We also opted to use a breatheable bumper. I can't even imagine ignoring the warnings about the increased risk of suffocation and SIDS from regular bumpers. I also hear regular bumpers are banned in Canada. The CPSC is investigating infant deaths tied to crib bumpers:
http://healthland.time.com/2011/01/06/are-crib-bumpers-a-...
The person who says they frequently check on their child that sleeps with a regular bumper -- suffocation and SIDS are silent, and brain damage or death from oxygen deprivation only takes moments. You can't possibly check on your child frequently enough to prevent it.