He isn’t saying you need a custom kernel to root the phone, he’s saying you need a custom kernel to use the HTC button. As far as I know, he is correct.
I used this app for a few weeks on my Nexus 4 and I didn’t notice much of a difference. Additionally, it hampers your phone’s function by turning off all notifications during idle periods.
I’ve been pleasantly surprised by the battery life, especially compared to my Nexus 4.
I’ve been getting home from work with 70 to 75 percent battery left after about 10 hours consisting of one hour screen on time and 90 minutes of streaming music/podcasts via bluetooth in my car. The battery seems to do phenomenal both during stand by and when streaming music with the screen off. In case it isn’t clear, the phone is not charging while I’m in my car.
I fortunately cannot comment with regard to text messaging and gaming however.
