the advantage of newton is its deterministic solver which makes simulations more robust compared to the other popular physics engines. the disadvantage of newton is that it isn't directly built into a6!

i think the standard ode solver is O(n*n*n) and newton is O(n*n) worst case so newton currently is faster aswell! there is a new ode solver in the works which is O(n) but i don't know how it will shape up stability-wise...