I have pondered R2R question for some years after hearing your machines Alan at Nebo?? They wiped the floor with everything else there with their sound quality and are indeed to my mind beautiful pieces of Hifi equipment that can stand out as a statement piece in a set up. I am sure for me the SQ alone would be the main reason for buying one.
But....... expensive to maintain and keep running unless you can do work yourself. Parts are going to become harder to find and setting up and playing tape is a little more involved than swiping a glass screen full of digital files! Unless you are committed to R2R way of life they may fall into a secondary usage or third piece of kit in your Hifi system rather than be used as a Prime source?
So unless you have a good deal of cash, expertise and commitment to using tape and space to install it they are indeed probably always on the wish list if only for looks and SQ?