Sundial, those seats have been around for a while... but whenever we (my boys, partner and me) have occasion to discuss them, we come to the conclusion they are great for potential crashes...

When cyclists stand, many tend to use their thighs on the nose of the seat to help with steering... without the nose, a key part of riding style would be altered.

On the other hand, I dont know anyone who has used one... but I do note I have not seen them on pro-cyclists bikes - for bunch racing or for timetrials...