Depends in age of child and type of toy.
We have Trofast in DS's room and it is absolutely perfect - Duplo, cars, Playmobil bits and bobs (he's 2) and a couple of Playmobil cars/planes sit on top.
We have the old Expedit on DD's (5) room. It's a bit hit and miss, tbh. She has quite a few big Playmobil things - some of them fit perfectly in the cubes and thus look a lot neater, but there is a jumble of stuff on top that's too big to fit e.g. Pirate ship and it looks so untidy. She also has a 3x2 unit in castors with crates, used for Lego, all the Playmobil contents (people, accessories, etc), and similar. These wouldn't have worked in the inserts for Expedit - too deep, not wide/long enough for good rummaging. On the other hand, the Expedit shelves are very useful for mixed books/toys and the drawer inserts are good for her 'important bits and pieces'. At the moment, she has two cupboard inserts unused, and two pull-out box inserts unused. The crates in the 3x2 are stuffed, and she has a fabric storage bag in her wardrobe full of dolls, dolls' clothes and accessories which couldn't be stored in the Expedit due to size.
I can see it becoming more useful as she gets older and the books and toys get smaller, but don't think it will ever be perfect for Lego and Playmobil. The Trofast unit, on the other hand, is great for small children but is very utilitarian, and is limited to the drawers - we put shelves in another upright Trofast unit and use it as a bookcase and display unit, but because there's no back, everything falls down behind. I can see it being outgrown fairly early on, but has a longer life for children interested in Lego, Playmobil, cars and trains and other small but chunky parts. Less for complete toys, books, puzzles, jewellery/beading/other teeny tiny parts, etc - spaces not big enough, trays too big, even the shallow ones.
We definitely thought of both as make-do temporary options - we're planning to move house at some point reasonably soon, and will probably go for some kind of mixed modular storage like GLTC's Northcote or Aspace which will last into secondary school. I can't see Trofast earning the space it takes up past around 8 or 9, when DS will need more storage space for clothes, sports equipment, books and a desk. Expedit/Kallax may still be useful at that point but again it's the lack of versatility that will eventually let it down, and the increasing need for other furniture.