It seems to work well.  Charlie has this funny way of sitting on the side of his litterbox while eating the hay above it– like feet in the bin, bum on the edge.  Sometimes he so engrossed in the hay that he loses his balance.  I find if I pull the box out from the corner I just get a pile of hay (and poops) in the corner.  The corner box holds just about as much hay but gives him a little more room to eat.  The bars have a little more space between them at the corners.  Charlie can stick his nose between them and pull hay without having to go in from the top.  That said, the bars might be a little wide for an exuberant bun with a smaller head.

Here is our other rack, this works very well too.  We were looking for a second one at Target when we found the corner rack: