Yes every body has their opinion and mine is most people did not learn to ride a bike without training wheels on it first. Once that person was able to ride the bike with the training wheels then they were removed and the person had to learn to ride the bike with out them. Once the training wheels were removed they did not crash their bikes near as much, if any, as if they would have if they started off trying to learn without them in the first place.
So, of course, I think the same applies here to flying the nexstar with all the training aids on it for the first flights, besides the AFS. Since the person who bought the nexstar is more than likely this will be his first flight I would leave them on because you can remove them at any time and yes the brakes do slow the plane down so that means that "gadget" must not be a "gadget" if it works. Why not start off slow and then grow into it.