I don't understand what you people do to your phones the "make them slow down"
I have had the S6 Edge since April 9th, I don't clear an cache, ever, and my phone is FAST and LAG Free to this day.
Touchwiz on the S6 is a billion times better than ANY previous samsung. It's SO good, I haven't even installed a launcher.
The default keyboard calendar, message app are Really Good. I haven't felt the need to change anything on the phone.
I also use widgets. Still no slow down.
If you phone "slowed down to old pentium speeds" its because you did something wrong. I own the phone, and it does Not slow down.
I would call that a straight lie based off my phone being as fast as day one, 90 days later.
Battery: my phone makes it thru every single day, all day, with no mid day charge. I don't even own a car charger.
I am honestly Not a samsung fanboy. I have had a few samsung phones and sold all of them, including the Note 4 because of LAG.
The S6 Edge is NOT slow and it lags about as much as a Nexus 6.