For the forces involved in top-roping, I don't see why a good old-fashioned tied cordelette isn't just fine.
Toprope anchors seem like a situation where the cordelette really shines. If the route doesn't wander, you don't need much in the way of dynamic equalization. And the monstrous redundancy of a cordelette is comforting when you consider that no one is up at the anchor to watch how it behaves when loaded.
At a belay anchor, you have a belayer standing there. If the anchor gets loaded in a funny way by the second or by the way the belayer hangs, and it starts rubbing against a sharp edge, you can do something about it. Any unpredicted problems like this at a toprope anchor could go unnoticed for too long.
I've been the proponent of a self equalizing version of the cordelette, but I use the old fashioned version more often when setting up TRs.