SPD's are not and will not be as secure as road pedals. They are designed to take dirt, be recessed and walked in, and be easily releasable. Simply put they don't work as well in a road/sprint situation. As far as I'm concerned unless you need the dual sided aspect (then use Speedplay/Crank Bro's/Beebop) or want to walk in them there's no reason not to just use road pedals. I don't race mtb but do you need any of those things mid race or is it just nice to be able to walk afterwards. What about Speedplay Frogs? Oh, and I can also pull out of SPD's on demand. I find that if I toe up hard it's near impossible but with a yank up at the heel (or without a stiff ankle since it works out the same) I can pull out with any cleat rotation.