My wifi connection to camera fails pretty regularly.  And so far I've primarily just flown the drone over open fields in the country, with little or no interference...

I'm a flip-phone guy.  I only bought the Samsung Galaxy S3 to pair it with my Phantom 2 Vision. Is it true that my wifi connection to the drone will be enhanced if I get phone service activated?  This seems far-fetched to me, but I feel obligated to check.  You see, I'm smartphone illiterate---or at least I was a month ago...

My Phantom wifi connection works fine with my iPad Mini, and it isn't even capable of a cell connection.

I use the S3 and it works perfectly, from the phone menu at the top, turn off mobile data and Bluetooth, never lost connection with it apart from flying out of range.
And NO its not true that having a phone service will make things better, not have one is better.

As far as I know, phone service operates in Mhz and Wifi operates in Ghz so activating phone service can not affect wifi connection.
But a newer smartphone's wifi module may perform better than the one from your S3
Just my idea~

I stuck a small square of masking tape to the memory card, hoping for a more permanent lock.  In mid-flight---recording successfully---and then connection fails. I try to regain it---and have been getting message saying "no memory card."  
So, I'm trying a slightly thicker card----first test successful. I'll know more tomorrow.  

I don't have a smart phone, but I do have and Ipad Air (no data plan, Wifi only).  No problem using it with cam, worked great.