I just placed my first order with them last week and I could not have been happier with their customer service, level of professionalism, fast email correspondence with me when answering questions I had asked, and the quality of my items.
Last week I had ordered two autographed Mario Lemieux pucks from them and not only was I beyond thrilled with the beautiful quality of both of Mario's signatures, but the fact that each puck came already packaged in one of those plastic cube puck holders and the certificates of authenticity were carefully placed in each cube as well was an excellent and very convenient touch. I've also bought signed pucks from Frameworth and while those pucks looked great as well, they were just packaged in plastic bags (no cube included) and their COA's look like little business cards that were in little envelopes. Plus at least in my experience, Frameworth's customer service wasn't as great as the level of service I had gotten from the people at AJ Sports World.
But yeah I'm not 100% sure if that signed Tangers jersey that AJ's is selling is an Authentic or an RBK Premier. But if you emailed them and asked, I'm sure they'll let you know.