If numba is installed, we should @jit(nopython=True, fastmath=True) compile the model when we lambdify them. This should of course be optional. If numba is not installed everything should work out of the box, and if it is installed everything should work faster. In addition, there should be a flag/option somewhere to never jit the models, just in case there's issues. Finally, the arguments to the jit function should be user-providable.