OP:
If you don't want to open up the Mini (it's a tricky job, with pitfalls inside), you can buy an external USB3 SSD like this:
http://www.amazon.com/exec/obidos/ASIN/B00ZTRY532?tag=delt-20
Then, plug it in and set it up to be "the boot drive" (the Mac doesn't care if it boots from an external drive).
It will run MUCH faster, and you will be VERY happy with the increased performance.
Actually, you can do something similar with the MacBook Pro.
Buy a 2.5" "bare" SSD, and "swap it out" with the internal hard drive.
It's a simple, easy procedure that anyone can do. A 15-minute job.
Go to ifixit.com to see how to do it.
If you get an external USB3 enclosure as well, you can put the old hard drive into it and use it as a backup or for extra storage.