I doubt I lost 1000 feet doing it, but it was an eye-opener. If you're at 4500 feet, try it. As soon as you're flying backwards, pop those toggles and hang on. It will give you a lot of insight into what's going to happen if you decide you have flared too high and release your toggles on landing. I actually have a jump where I did a stall and popped the toggles on video. The first time, it scared the hell out of me, I didn't think that 210 boat could move that fast. It's a good thing to know, just make sure you're up high.