Hi Matt. What happened? In heavy air crashes its hard to remember what happened between the "oh shucks" I'm going to crash and finding myself in the water but in the end I simply did not get far away from the boat. Other than the nuisances mentioned below I've never felt retricted or endangered by using this method.
I've had some pretty good "get offs" with this set up. A couple of pithpoles, a high side (upwind capsize) when a forestay broke and a couple of slow and easy wild thing gone too far roll overs. I have the ring of the shackle on the sheet and clip the opening end to the shoulder strap of my PFD. After a capsize I make sure I have a good grip on the boat and then I release.
I tried the snap shackle down by the spreader bar but it kept the sheet too close to the hook for my liking and too much tangling with the feet. Up high on the shoulder strap is better for me at keeping it out of the hook but it still finds its way there sometimes. I check that the hook is clear pretty often. The sheet does tend to get wrapped aropund the feet more often than without the shakle, something else to get used to and keep clear. One good thing is that even if I drop it the sheet is always with me as I move around the boat.