This is the first time I have ever heard of this and I have been in cellular sales for almost ten years. I rarely shut my phone off for any reason, and never have any issues with battery life or reception. I have actually found turning the phone on and off wears batteries down faster than just leaving them on! But hey, if it works for you, great!
Yes it does help me, sometimes when I have issues with my phone it helps it a lot. I work for AT&T and they advise us to inform the customers about this, and to be honest I didn't think it would work but then I started to do it with my phone (I have Verizon, obviously). To my surprise it actually works, so it was just a friendly comment to people in case they have issues with their phones. I work for tech support for almost two years already, so that is how I know. Different departments have what they need to know. I was in sales for a year and had no idea about this, then I got a job for tech support and this is where I found this out. Pretty neat, well at least to me ya know? Well to each their own. 🙂