Even though we deal Kenwood, we only do because some still ask for it by name (mainly headunits though). All experience I have had with their subs could be classed with "all the rest". Never performed better than any other run of the mill subs but no one ever had any complaints after the install either. If they sound good to you, run with it. As far as custom box, I don't know if I would spend the extra money on someone else doing it just for the Kenwoods. Prefab boxes with the correct air volume will be adequate and save you about $150. If you are stepping up into a JL or some other comp. type subs, then the custom box $$'s will be worth it...