I recently acquired Volume 1, completing my set. So far, I am pretty disappointed. There seem to be many types left out, for which I need to search online. In my personal opinion, they are not too easy to use and provide little value vis-a-vis the high cost (the complete set cost me INR 21,791), considering that online references such as Wildwinds are completely free.
I also acquired the (much, much cheaper) single-volume tome ERIC II (The Encyclopedia of Roman Imperial Coins) by Rasil Suariz, which I am finding quite useful. It also covers Byzantine coinage!