With an adapter kit I have the HDD installed in place of the Super Drives, which I've used in the four years up to 3 times eh ... This much file storage space has remained.
My operating system and all the software I have installed on the SSD.
For this, the 250GB is more than enough!
All in all, the increase in performance and performance in my 4 years old Macbook (2011er) now so large that occurs to me, as if I had a brand new!