That's great - benchmark 2 is essentially a bunch of useless work, and it appears to really speed things up by making sure we only actually touch the DOM every 16ms, instead of constantly.
I'd imagine a Backbone integration with React would get us even closer. I'm not sure if it actually makes sense to go too far with an LM conversion as React appears to do a better job. But LM could certainly benefit from waiting until RAF.
I'm sure doing a similar thing with LayoutManager wouldn't be too hard. I think LayoutManager uses _render internally too so you may want to call it something else.
It also definitely does make the benchmarks faster http://danshearmur.github.io/backbone-fast-view/