I only just started using the new ones today, but I actually found that the packet I was using were different - they didn't leak, but they just seemed like they were full of water and almost sloshy kwim? Like the crystals didn't work properly. Although they did seem thinner when I got it out of the box, but they have gotten thinner each time they change their design. But I have never had Alister leak at all in huggies ever, he's just not a big piddler LOL.