Secondary Hard Drive I have a mid-2012 13" MBP with a 750G,5400rpm,HDD and I am going to remove the SuperDrive and add a 1TB Samsung Evo 850 SSD. 

My question is, I am going to run my operating systems, macOS and Bootcamp Win 10 on the SSD and have the HDD for storage, is there any benefit to replacing my HDD with the SSD and then replacing the SuperDrive with the HDD? 

Just curious if there is any read/write difference between the SuperDrive connection and the designated hard drive connection.

Thank you.
Since your Mac is from 2012, both the connectors are the same speed.
As I quote from this article:


  2012 Models - Fully support SATA III (6 Gb/s) in both the HDD bay and the Optical Bay. I'd recommend just leaving your HDD in place (more sound proof, less installing) and put your SSD in the optical bay.


Keep in mind that Macs that came with a superdrive are not able to install windows 10 via usb in bootcamp.You will have to install bootcamp with the cd drive still in the machine.
At least that was the only way for me (mbp early 2011)