What works better - same thread followups or fresh emails?

In the cadences i run, 2,3 or 5 step/email cadences - i always thread all follow ups or steps under the subject/thread of the first email.

I would like to know if people/users have received better responses with new subject lines for the follow up emails instead of threading them. 

For example - i could be talking about a suite of products under one umbrella offering but then choose to have different subjects per new product follow up. or new subject for each new use-case follow up