I have had both c-j and AI units. c-j service has a reputation for being available and responsive, and that has been my experience to date. With regards to AI. I have found them also to be responsive and helpful. Jerry in service, and Art Ferris (owner and chief designer) have been responsive, helpful and willing to give of their time and expertise. Re: c-j 14 vs A.I.,,,,,,with it's absence of a cathode follower I have found the AI (I am presently running a modulus 3A with a MV-55) to be clear and sweet without being euphonic; and without the veiling traditionally associated with cathode followers. Plus, it has an excellent phono stage that will accomodate MM and higer output MC cartridges. It is not fatiguing, yet resolves detail well. Check out both companies web sites., and try to get a home trial if you can.