These catch drivers' attention. I place them in the street and we've heard feedback from the neighbors that they appreciate when I place them outside -- they see them and know the kids are playing. So far they haven't toppled or faded.

A few very minor critiques:
1) While they are bright in color, some reflective material wouldn't hurt. I applied reflective stickers, but the sheen on the plastic didn't let the stickers adhere well. Or maybe I just had lousy stickers.
2) For the sake of storage, they fold flat but they don't "click" into a locked position, and depending on the temp outside and if they're in direct sun, the plastic softens a bit, meaning they don't fold entirely flat. Not a big deal. I bought them for how they work at alerting people to children playing, not how they stack in my garage. But if the latter is on your spectrum of key attributes ...
3) The kids legitimately took offense to the wording and had NO IDEA that the "slow" was a warning. They honestly thought it was a sign describing them ... slow children are playing. So yeah ... take that for what it's worth.

YA it could be a little heavier so it doesn't fall over in the wind but if you weigh it down a bit with a bean bag it is great to protect the kids

This sign helps out so much when my kids want to play outside and people are driving way to fast!!!

Love it - have an 18month old grandson. We put to up on the driveway when he is here so everyone comes up slower

Kind of flimsy and light. A slight wind will knock them over. One of ours came with a chip in it (plastic was torn away) but I didn't bother to return it-- to much hassle.