From my past experience anyway, the problem with Universities is that anyplace you want to order something from, needs to be "vendorized." This process can take decades, and/or possibly centuries in some cases. It's easy enough to order from Apple or Dell, but best of luck trying to order from NewEgg or OWC. In the latter cases our department always wound up paying for it up front (if the part was needed in a unit of time measurable in weeks, instead of months and/or years), and hoping to get reimbursed.
Anyhoo, Apple's SSD is ... mediocre. It's an SSD, it's faster than an HDD, if you're spending somebody else's money, then just check off [x] 512GB SSD, and if it breaks, Apple will replace it. If you can order it someplace else, do that then; but in my experience that's often not an option. You can't just issue a PO to <some random company> without vendorizing that random company, and that seems to take aeons when it gets approved -- often it won't get approved. Why not? It's almost impossible to say. Welcome to the exciting world of academia, "Hey, if I wanted a real job, I'd go get one, and wouldn't be hangin' out in the IT department of a university making 1/5th the cash I'd make if I knew how to do anything useful! Go 'way, you're bothering me, I'm playing WoW!"
BTW, I'm not saying that everybody in IT and purchasing who works at a university s--ks ... but, they do.