Buck Converter Control Scheme- Why isn't just a comparator not enough?
What you have here is a hysteretic-style buck converter. It may simulate well for a static load, but real-world performance may not be as robust as you'd imagine. A previous answer to this can be found here. In a nutshell, the switching frequency is dependent on the load and will vary greatly. This makes filtering out the ripple challenging. 

Try quickly changing the load during the simulation and see what happens.

Now this kind of supply would work well as a pre-regulator, fed into a low-dropout linear regulator. The output of that would be very flat and virtually ripple-free.