The KK is in a class by itself, there really isn't any competition for it but it has a very small possible customer base. My vote would also be for the Primo lineup, due to the oval design, plus they also have one round version, so all bases are covered.
Welcome to the forum, there is a wealth of information on using your Akorn here. Enjoy your learning process and don't be afraid to ask questions. There are some very friendly and knowledgeable members that will answer any question you may have.