I thought I got a defective set because one wasn't lighting up until I realized there is a small indent on the side of the dice that goes on the bottom and some have a little ring on the bottom to show you which direction it sets in. After fixing that my d10 charged and lit up just fine. They do feel a little bit cheap in the hands like a plastic rather than a resin or metal set. Overall they're not bad but they are a little finicky!
They work great! They don't take a long time to charge and last for a long time (easily my entire DND session). They are much brighter than I thought they would be, you can actually see them glowing even in a room with lights on. They also don't stay on forever, they turn off after some time which is nice. All you have to do is toss them and they will light up when they hit the surface you're throwing them on (as long as it's hard enough or you throw them hard enough). They are also the size of a normal dice set so they fit perfectly with my other sets. The case they come in also doesn't just seem like a charging case, it looks good. The numbers are easily readable when they are lit up too. For how much they are, they are definitely worth it if you want a bit more color in your dice.
Very satisfied