Before revision:  Model-free methods based on deep-learning provide an attractive alternative, as they can in principle learn the optimal filter from data, but to the best of our knowledge were never compared to current state-of-the-art Bayesian filters, specially not in contexts where accurate models are available.
After revision:  Model-free methods based on deep-learning provide an attractive alternative, as they can , in principle, learn the optimal filter from data, but to the best of our knowledge were never compared to current state-of-the-art Bayesian filters, specially not in contexts where accurate models are available.