I just installed the Samsung EVO Pro 850 512gb SSD into my HDD slot as i purchased a HDD model of the mac mini only. This SSD works like a charm, my boot time before with the 5400rpm HDD was nearly 2 minutes, with this SSD it is now down to 9 seconds! I highly recommend updating your mac mini if its an HDD only with an SSD as it will speed it up tremendously!

The teardown wasn't bad at all, i had tore down in 15 minutes and had it put back together in 15 minutes. The only trouble i had was taking out the HDD, Ifixit sent me a TR9 instead of just a T9 and the TR9 is bigger, it wouldn't fit but i stripped away at the screws and finally made it work!

There isn't a late 2015 model, the last model they made so far is the late 2014.

Dont buy the economy TR9 it wont fit in the screws, you have to strip them away a little bit to even get the TR9 economy in.