We've had the Trofast system for about two years. I like the smaller bins, but can't say I love the bigger ones. They fall out of the grooves very easily if there's too much weight in them. We've also broken the rims of at least two of the largest bins, again because of weight issues. Our kids also tend to leave the bins half pulled out, then they climb on top of the units (we have the low ones), and kind of carelessly use then bins as foot rests while they're sitting up there playing.
That said, it's nice to have such a flexible system -- I like that you can combine different sized bins and that it's easy to organize toys. Makes cleanup very easy.
DC1 -- 2005 DD -- 2009 DS -- 2011