I just got a mac mini 2014 entry level 399 machine. I have used it for a couple of days and notice a huge difference between that and the MacBook Air I have. I have browsed around looking at the options, my understanding is that I can upgrade the unit to a fusion drive by getting the cable required and an SSD PCIE. The alternative that I have also seen is to completely remove the HDD and replace it with a SATA SSD. I know the first option seems more expensive than the second, but what benefit is the first over the second and vice versa?