We have a 7 year old set of Picasso tiles that get played with a ton. But we now have more kids and the boys have been really rough on them so we’ve had a few casualties. So Santa brought a new set of tiles for Christmas this year. The Picasso tiles are great but the colors are limited and it’s just the standard shapes. These Cossy tiles are WONDERFUL. First of all the colors are gorgeous! They’re not standard primary colors that feel tired and juvenile. They’re bright and fresh and more variety in this set. We got all the same shapes we had before, but this set has a really wonderful selection of specialty pieces. Santa (or maybe my husband) built a great castle for the Christmas morning reveal. My kids love that they have more pieces to work with now and are really excited about the special pieces. This set totally infused new life into an already favorite toy!!I can not compare Magnatiles, but I had gotten Picasso as a more economical option years back because they were said to be the same in reviews with grommets as the only difference. Aside from the old set being scratched up and not so shiny and translucent anymore, you can’t tell a difference in the sets. The magnets are just as strong and construction and quality seem identical. Editing to add: I found some minor differences in the internal seams on some of the shapes. Doesn’t seem to change anything but the aesthetic. Pic attached of a few Cosy and Picasso side by side.My kids use these to build all kinds of fractilated structures. They also use magnet tiles in so many of their other games. They use them as fortresses and jails with superhero toys; they make ramps, targets, and garages to use with cars; they make targets for nerf guns and other shooting toys; they make domino falls; they make traps; doll cribs, and sometimes they just build.This is also the thing my kids play with when I see them getting along the best. They engage in cooperative imaginative play, and especially now that we have enough pieces to accommodate all 4 of them, there’s very little squabbling. They can play together or separately.This is the one toy set that I insist stays in the living room. The options are endless. It appeals to all ages and genders—my kids are 10, 7, almost 5, and 21 mos at the time of this writing; 3 boys and a girl.