it doesn't make the phone useless at all. i actually don't use wifi as i find it plenty fast on 3g. however, if i do want to use it, it takes about 5 seconds to turn it on. there's just no point in having it on wifi 24-7. when you want to browse then turn it on. also, i have the screen set at about 30% bright and find that it's actually better this way when i'm out in the sun and inside it still looks amazing. i leave gps on though. it's just like any electronic device. if you leave all the bells and whistles running, even when you're not using them, it'll drain the battery faster.