they seem like a good idea. however, i have read that they are similar to helmets - if you have a bad fall in one it really should be replaced as the foam pockets in the padding collapse (or something like that) and then it really just becomes a glorified & expensive vest! seeing someone having thiers for 6 yrs with multiple falls & not replacing... makes me cringe a bit. i would not keep a helmet for that long, even if i hadn't fallen on my head in that time. they age.