I always leave mine on all night .... main irritation is being woken by the "battery less than 10% - attach charger" klaxon in the middle of the nighy if I failed to spot it needed to go on the charger (my Xperia Play tends to last a couple of days between charges .... now got an N5 on order and that may need a daily charge - though I'm thinking of getting a Qi pad for that)I've always left my phone on (though only use it as an alarm if I'm away from home). The drain is insignificant (unless you live in an area with shocking reception).
The only irritation is the odd beep if I haven't muted it and the notification LED reflecting off the ceiling (at some point I will learn to turn the phone face-down before hitting the hay).
Quote the study, I want a good laugh. Also you must trust the device if you stick it on full power next to your junk every day surely?On, but with Airplane mode on. I only use it as an alarm when I sleep.
There have been studies that say that leaving your phone connected to WiFi, mobile networks, etc. can cause health problems. Not conclusive of course, but I'd rather not take the risk.