So I had a Galaxy S5 few months ago, and had updated it to 5.1 but it became laggy, much so that I had to restart the phone a few times a day. This Note 4 from T Mobile is on 4.4.4, but I checked if it had an update, and it does. But for 5.0. How is 5.0 on the Note 4? Or should I root it and add a Custom ROM?