I have to admit that every time I attempt mine, I end up ripping them off in disgust. Unless you're one of those women that models the Spanx and doesn't really need to wear them in the first place, everything is fine and dandy underneath but focus on either end, and well, it's not pretty. If Spanx is going to work for me, it's gonna have to be a full body version. I have skinny ankles so a couple of inches of overspill at that end won't matter, and I'll just stuff the other end into a pony tail and make it look like I have really thick hair!
And let's not forget the hit-by-a-car concern. It's bad enough worrying about wearing shabby underwear but can you imagine being carted off to hospital in huge great big Spanx. When they finally stopped laughing at you, they'd have to cut you out of them.