There's a list here made by Windows Central
11 things you should do first with the Lumia 950 or 950 XL | Windows Central
I didn't perform a hard reset of my 950XL, I simply turned it on and restored a backup of my 1520 and things are fine.
However, this is one of "those" kinds of questions where everyone who responds will have a different opinion.
If I were you, I'd use the phone as it is and only perform a hard reset if there's a problem that requires one. I'm not really a fan of performing a hard reset just because the internet tells me to...