You cannot take a CD, record it onto any type of other media, and make it better than the original source, so the owner of the store did some BS crap to sell the tape deck. The best thing that would happen is that the tape would sound identical to the CD if everything else was equal. You cannot make a better recording of an original source because the information on the CD is not there to make that happen.
Now what I will tell you all is this. I knew a guy who had a professional recording studio, when requested by a singer or a band to record a master in both analog and digital, thus there was a master tape and a master CD, the tape always sounded far superior to the CD. One of the reasons a prerecorded tape that was recorded from a master sound so good is because it is a true 2 track recording media, you have a separate track for the R channel and a separate track for the L, with CD and vinyl they artificially separate the channels.
It is true that reel to reel tape machines are making a comeback, but to get the sound that you want from it you have buy prerecorded tapes that were recorded from analog master tape, otherwise you're wasting your money. Those prerecorded tapes are also making a comeback and can be found on the internet, howbeit in limited performances at this time, but more "should" slowly become available.