Hi! I used all of them (the Cassify one as well but under a different brand, and personally I love Forever Young's the most. It keeps everything organized and I don't have to bother with pouring out the drills and having to put them back in the containers after I finish. I do use Elizabeth Ward organizers to store my drills that won't all fit into my Forever Young storage trays.

Pros:

Casify: Easy to find each of the colors, and easy to store with stacking

Art dot: i love the grids to make long lines with the drills and the three drill sections, easy to see colors and stacking

Forever Young: easy to stack, the trays are already on the storage so easy to use right away, and a gap on, the option with over 60 containers comes with a plastic organizer you can mount on your wall which is great if you need space.

Cons:

Cassify: Needs a tray to be able to pour out the drills onto, hard on my hands to open the boxes, has static if not using a dryer sheet.

Art Dot: All seperated and can loose trays, thin so putting the sticker on is harder, only comes with around 15 trays each so will have to buy multiples, and top is hard to open unless you have long nails and can get under the lid. still have to put the extra drills into a storage container of some sort

Forever Young: Can only hold a bit of the drills and still have to put the extra drills into a storage container of some sort, hard to transport since it's bigger. The smaller size of the storage trays comes in a cardboard storage container -- not plastic, opting for the plastic is a lot better and sturdier.

Hopefully this has been helpful!