Off of quick tap penalties, you don't get tackled immediately, but you are charged by rabid defenders. If you run an angle, you should get several meters. At rucks, I was surprised how quickly the scrumhalf recycles the ball. I've had my no. 9 get there just as the ruck was set and pass it out immediately. Other times, I've cringed as player after player entered the ruck but there was scrumhalf in sight. I thought the ref was going to blow the whistle. Finally, he showed up and got the ball out. But by then, he defence had reset. It depends on the situation and the scrumhalf, I suppose. And contrary to what others have said, I've been able to pickup out of rucks and actually break the line and start an attack. It doesn't work all the time, it just depends on who's picking up (not always a scrumhalf) and if the defense had the fringes covered.