I have a Leate I no longer use (PM me for details if you're interested).
Once adjusted correctly it was easy to put on over my jacket and comfortable to wear. It took a little getting used to, but after a couple of weeks using it I forgot it was on. It did restrict me doing 'lifesavers' a little, but not to any significant extent.
It fascinated toll operators and police in France and I had to learn to explain it was "comme un casque pour le cou".
The only real problem I had was that it made an extra bit of kit to store securely when off the bike.