Ooh yeah, just tried it, much improved.
Encountered my first bug - setting a delayed pin lock after sleep, 10 minutes for example, has stopped working. Now it's asking for pin every time. Tried a reboot but to no avail. Annoying, as this was a major omission from GB TouchWiz, shame that the option is now there but it fails to work, hmm.
Actually, it's weird. If the screen goes off by itself, say after 2 minutes, it doesn't ask for a pin immediately after when you try to resume from sleep. If you put it to sleep yourself, it DOES ask for a pin next time. Bizarre.