I have the 54 volume first edition sitting on ridiculously overstuffed bookshelves.
Neither the authors nor the reviewer apparently thinks much of The Great Books. To be honest, though I've owned them for nigh unto 30 years, I've read very little from them. They've been useful the few times I've needed to dig in there after some tidbit or other but that has been rare. The reason I own them differs from what the reviewer claims for other owners. I own them because they came available to me for a paltry price of some $50 which included The Annals of America - my set of which may be of extraordinary value since it consists of 19 volumes rather than the 18 volumes available from Amazon.
I have found the Annals useful from time to time. Certainly moreso that the Great Books. But I always figgered the Great Books were an investment in the future. Something I'd be able to drool upon in my dotage. Alas, it may just have been $50 poorly spent.