Is it me or does 3 inch flexwatt not provide a big enough heat spot on tubs 28 quarts or larger?

In my bigger rack I have doubled up the 3 inch tape because I always felt just 3 inches of a heat spot is too small. But looking at others racks, I see some people only use the 3 inch...

My wife thinks im being too picky/anal about it, what do you think?