So i have a theory on why halos form, other than due to the curvature of the screen

My theory is that the adhesive over a relatively short period of time, loses moisture and tackiness, especially around the edges since it is closest to the outside environment being exposed to air. Some may be worse than others. As some and myself have done, they added heat by using a hair dryer (I used the high setting), thereby slightly melting the adhesive and making it stick again. So far after one night, halos have not returned. So yes, its worth the extra 5 minutes it takes to remove the halos instead of spending more time, effort and money to find that "perfect" screen protector.