But it's very nice hardware, for a fair price.
If what you want anyway closely matches an available Mac hardware model, that may well be your best choice. But if you have other specific needs, then usually you can get a better fit in the commodity PC hardware space.
If price is a key selection criteria, that "better fit" can include a lower price, in which case your hardware might not be as nice as Mac hardware, but it may meet your needs just as well, if not better, for less money.
For a couple of my relatives who just need simple documents, email and web, I build systems for a few hundred dollars, plus monitor and printer. I could do that with a Mac Mini, but it would cost two to three hundred more.
For my teenage son and his friends, I build gaming systems for perhaps a thousand to fifteen hundred dollars each. I could do that with a Mac Pro, booted into Windows (serious games are exclusively Windows), for perhaps an extra thousand dollars.
The same applies on the high end -- for my day job, I work on ten thousand to ten million dollar systems, built mostly from commodity PC hardware ... very select, very leading edge, industrial strength, commodity hardware. In another window, I just logged off a system with 2048 CPUs and 4 terabytes of memory (RAM, not disk). It was running a single Linux boot, not a cluster. Apple is not one of the vendors we deal with.
I am having a bit of trouble that it is not a cluster. It seems to me that even with re-entrant libraries, a single Linux boot would be tripping all over itself, just with HD access speed, with library calls from 2048 processors unless there is some kind of distributed library system. Can you provide more information?
If I recall correctly, the Virginia Tech Apple G5 Cluster of 2200 processors has a total of 17.6 Terabytes of RAM. There are a couple of larger Apple clusters that have more. I read the US Army's COLSA MACH5 Apple G5 cluster has 25 TB of RAM.