The best Mac made is what they call the cheese grater . You can get in it change pieces add pieces it's more like a Pc. But iMacs are dire. Why they can't put a hatch in back to Acess and change the hard disk drive I'll never know . So instead I have to remove the front glass bezel ,then remove Led screen removing five cables between screen and motherboard or as Apple call it the Logic board.
Then you can't put a standard Western digital hard drive in it has to be one to have a temperature probe connection. The lastest Mac Is a beautiful fast machine ,but trying to add anything to it is troublesome . You see it looks great on paper but soon as you start adding cables to it it looks nothing like the pictures hence the name a Trash can. I'll let you know how fitting the new Harddisk drive goes. P.s Apple have the looking good thing down to a T but functional and servicing is awful. The newer ones I believe are even harder to update or add things to.