I think I would be a bit leary of this kick. It seems like the type of strike that could cause as much damage to you as it does your opponent. That is, if anything goes wrong in the delivery. The toes are not exactly the sturdiest part of the body, especially when you take into account the amount of force a leg can produce. As anyone who's been under extreme pressure to preform knows, when the adrenaline drops, 50% of your training goes out the window. Now I don't know about everyone else but I'm not a big fan of things going wrong at vital moments. Add all of that to the fact that it's not exactly brilliant in a self-defense situation to lift your leg off of the ground high enough (above the level of your own knee) to hit a soft target, and this strike just keeps seeming less and less practical to me. I prefer to work with techniques that have low potential for backfire.