IOCTLs versus netlink

[Kevin Wilson]

Hi,
Can someone please explain why are netlink sockets a better
communication method between kernel space and userspace ?

I know that with IOCTLs we cannot send asynchronous messages to
userspace from kernel, and with netlink we can.

Are there more things to it?
I once heard something about that when passing with IOCTL a pointer
from userspace, you can mess it, by advancing it too much for example.
But I am not sure.

regards,
Kevin