In regards to the whole battery redundancy and TX battery failing, How many times have you heard someone say "my TX battery failed" right after a crash? After being in the hobby for over 20 years, I have heard that a grand total of ZERO times. But I have seen guys find out that their Rx battery took a crap on them in flight at least a dozen times. So what is the chances of the Tx battery dieing in a low amperage draw system, i'd say pretty slim and if it does happen to you, its just bad luck and probably a once in a thousand thing to fail. So my question is why NOT install a redundant battery in the airplane if you have the space to do so? The only thing that could happen is a possible battery or switch failure.. which if that was your only battery, you'd be out money. but if it was your 2nd battery, you'd at least be able to land and figure it out (that is if you charge after every flight).

truthfully, it comes down to each person's personal desires and opinion on redundancy. Some Like to have all the new gadgets, etc and if it makes them happy, so be it. If you have been doing things your way for years and it works fine for you, so be it.