Anyone using 3M paint defender or just use clear bra?

I was just curious what most of you are doing about protecting your paint from chips. Has anyone here tried 3M's paint defender? It looks pretty easy to apply and remove. I'm sure it doesn't offer quite the protection of a heavy duty vinyl wrap, just wondering if it will help with the occasional rock pelting a during a run. Or am I better off just getting Expel put on after I fix my rock chips?
Any comments would be appreciated.
Thanks.