I realize I am very late to this party but I thought I'd offer my opinion anyway.
I do not use and likely never will use a "clear bra" product. I believe they are fine for basic paint protection such as from bugs and some very minor road derbies but I believe their effectiveness is very limited as compared to their cost.
When I want REAL protection for the front end of my vehicle I use a high-quality vinyl bra - over the 30 plus years I've been driving high-performance vehicles I've literally saved myself many hundreds of dollars of damage to my vehicles that a clear bra would simply not have provided effective protection against.
That said, I've nothing against clear bras and I realize that for those who drive their vehicles every day, they probably make more sense than a vinyl bra (they certainly require less "work" overall). That said, I find their usefulness a bit lacking for me.