Mine have been maxed a little over a week now. Long made short...the lower levels were absolutely useless when faced with the typical player over 4000. L14 can be used with Minion Drops in place of one camp of Drop Ships for certain bases. L16 will work with some weaker, lower level bases. I found neither very compelling and anything lower was miserable. Other than that, you are generally looking at L18 before they are usable and they are generally paired with Super PEKKA. Some mixed-strats can use them as well, but that’s more advanced play of course. I use them occasionally with Minion Drops where the base fits it.