I would gladly buy the AHD5 but for one thing: no CD-ROM version. I owned the 4th edition, which came with the CD. Having installed the full dictionary on my computer, I used it virtually every day for writing and editing, and found it extremely useful, particularly the usage notes. However, the old version won't work on a 64-bit computer (Windows 7). The publisher even included the CD-ROM for free with its 4th ed. collegiate version, but has now apparently decided to abandon it completely for mobile apps. Bah! (I don't even have a cellphone.) I wrote the publisher twice to inquire into this, but they did not deign to respond. Result: No sale here until they offer the CD. (I am forced to use the Merriam-Webster Collegiate, 11th ed., which is no nearly as good. I also have the entire OED e-version installed on my computer, but it is less useful on a quick-and-dirty basis.)
The old one is 16 bit...lot of trouble, BUT you could run windows 3.1 through DOSBox (on your 64 bit machine) and then launch it that way. I agree with you entirely, I think it's an absolutely beautiful book to look at, but it's huge---ten pounds--and when I want a definition I'm not looking for a nostalgic experience. I've tried to make myself look the forth edition and hardly ever do. When I bought that I didn't realize it had a CD, and back then I was used to opening a book---now, there are just SO many advantages to the electronic alternative. If it had a CD yes, without, no.