Seen it, never used it. Too much hassle IMO to use it as a replacement for PP seeing as I'm not sure how it could actually be anymore secure. Plus, 99% of the time, at least in sythe transactions, the person who needs more security is the person buying. Most scams come through the form of account recoveries (obviously).
I'm sure it's nice and easy to use for sending money to family/friends. I use venmo or square cash for that, though.