Gelatin powder vs Gelatin leaf when and why
I have never personally noticed a difference. I saw that there are other answers which say that a difference exists, but the points made are not inherent in the form (powder or leaf). The difference (which is already slight in itself) is more likely to appear between different brands of gelatine, and it can simply happen that in some market, the available leaves have a quality which the powder doesn't, or vice versa. It is like filling olive oil in square or round bottles: the final shape is different, but it has no effect on the content. 

There can be some slight personal preferences in handling one over the other - as you said, for you blooming the powder sometimes fails. There is nothing universal about that, I suspect that every cook makes fewer mistakes with whichever they are more familiar with. I remember how comically I failed when I tried to bloom leaves for the first time. 

For me, there is no culinary reason to choose one over the other.