From a end state perspective, it does not matter . . yum update after the install (of either) ends at exactly the same place.
I will not be running any updates, because I need to keep a specific old version for software compatibility. I don't know which ISO the USB stick was made from.
Also, a 'uname -a' from the command prompt will tell you ..
This would be perfect; how do you get to a shell from the installer? I only see the option to install.
That is also the only version which is tested at any point in time.
(latest + all updates)
Tested by whom? Each software vendor may test and recommend differently.