Only thing Sense is missing is real-time SPO2. And that's software.
So, the Versa 4 will be losing skin temperature sensing and gaining...nothing. Nice.
My Versa 3 has never worked correctly since I got it. I'm fact, I've had to replace it once and still doesn't work. It won't sync to my phone but occasionally. Never has it recorded any workouts. Never get my texts or phone calls on it. I wish I never got it. It's not cheap! I may never own another Fitbit product again.