CS First with existing Scratch accounts

I am revisiting Scratch with its new teacher functions and am also getting started with CS First.  I recently set up my first class of students with a studio in Scratch but have yet to start with the students.  I have also recently created my first club in CS First intended for the same class of students.  Can anyone advise on the pros and cons of using each independently?  Can I have the students follow the activities in CS and login to the New Scratch Studio account so I can take advantage of the new features of Scratch? Or is it better to simply have them log into the Scratch account created in CS First?

If anyone has advice, it is appreciated.