Wow, I'm surprised people would run that aggressive of a pedal on kids' bikes. (Looking at those AESTs) Those things do not look fun at all to take a shin-scraping (or worse) from. You own stock in Johnson & Johnson?
Seriously though, do the kids run pads or anything along with them? Have you ever seen what one can do to flesh? I'm not some wildly overprotective dad by any means, but I wouldn't feel safe putting my 9 y/o on a set of pinned pedals with any more than a couple millimeters of protrusion and body without sharp edges, and he can jump a car. Having taken a few people for stitches from pedal whacks in the past, I can tell ya it's a crappy way to end the day, and is rumored to hurt. For a young kid, something like that might be enough to discourage them about riding in general for awhile. Not to mention give them some nice scars.
Not that it's any of my business what anybody puts on their bikes, but it's just one of those things that when I see it, I cringe a little. Learning to ride bikes involves crashing, specially off pavement. It's inevitable; that's how we learn. No need to throw a couple meat tenderizers into the equation. Performance wise, I can't believe any kid that's not racing DH or competing in trials would really need a set of pedals with that much bite. I regularly watch people throwing backflips and flairs and such on nothing more than the plastic ones. The trails most young kids will be riding aren't going to be anything where it's worth adding the risks of pedals like that IMHO. You'll get plenty of grip from something a little less...sharp.
Sorry to ramble, just hate seeing kids get dinged up unnecessarily.
