[jsf01]

Absolutely. setInterval with a very tight interval runs the risk that your code execution time eventually catches up with the interval duration itself. Using setTimeout and raf recursively avoid this problem, but they do add a bit of baggage themselves by growing the call stack via many many recursive calls.

Edit: looking into this some more, it seems like the recursive methods might not actually grow the call stack due to being asynchronous. Their only added baggage is the extra closure which would be negligible. Anyone know if this is actually the case?

[fenomas]

There's no recursion involved with RAF or looping with setTimeout. In either case the "anim" function doesn't invoke itself, it calls a scheduling function and passes itself as an argument.